Epoxy silane oligomer and coating composition containing same

ABSTRACT

A process for producing an epoxy silane oligomer including a reaction glycidoxy silane and/or cycloaliphatic epoxy silane having 2 or 3 alkoxy groups and, optionally, a copolymerizable silane other than glycidoxy and cycloaliphatic epoxy silane, with less than 1.5 equivalents of water in the presence of a catalyst, wherein said water is continuously fed during the reaction.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of copending U.S. applicationSer. No. 11/100,840 filed Apr. 7, 2005, to which priority is claimed andwhich is herein incorporated by reference.

BACKGROUND OF THE INVENTION

There is extensive literature describing the use of monomeric epoxyfunctional silanes. Such silanes are used either alone or combined withappropriate polymers. However, one of the main difficulties in the useof monomeric epoxy silanes in water is their sensitivity to hydrolysisand condensation which is difficult to control. In addition, thestability of the epoxy functionalities when using the monomeric epoxysilanes in water is difficult to control because of the tendency of theepoxy functionalities to exhibit ring opening.

The use of pre-hydrolyzed and pre-condensed silanes is one answer tosuch concerns. A pre-hydrolyzed and condensed silane can be anoligomeric structure that has specific features like controlledmolecular weight, usually good film formation capabilities anddispersion properties because the silane terminations are alreadypartially or totally condensed, and faster curing rates. This aspect ofthe oligomers makes them attractive to the coatings industry as itbroadens the field of applications and also helps to get fasterapplication or formulation properties. However, the high molecularweight oligomers can condense further to larger siloxane networks, whichresult in the formation of structures that are difficult to makewater-soluble.

For example, U.S. Pat. No. 6,391,999 discloses multi-functional epoxysiloxane oligomers for use in a solventless or solvent-based system.These multifunctional epoxy siloxane oligomers have high molecularweights and an insignificant amount of residual silane functionalgroups. Thus, it is very difficult to make the oligomers water-soluble.

Another disadvantage of the use of monomeric epoxy silanes is that theyrelease a large amount of volatile organic compounds (VOCs) expressed asalcohol content introduced by the alkoxy functionalities.

A general trend of the industry is to decrease or eliminate the releaseof VOCs or hazardous air pollutants (HAPS). It is desirable to reducethe methanol content of any structure that could be involved incoatings, adhesives and sealant applications.

It is also desirable to prepare water-based coatings, which areresistant to chemicals as well as corrosion resistant based on metallicpowders like aluminum, zinc, bronze and other metallic or organicpigments. Metallic pigments being sensitive to water, there is also aneed to have superior protection of such metallic powders in wateragainst a well-known mechanism called hydrogen evolution.

It is also desirable to design water-based coatings that have superioradhesion properties, mechanical or chemical resistances with outstandingweathering behaviors and that can be applied on a variety of substratessuch as metallic or plastic substrates, cellulosic or naturalsubstrates, concrete and any other material generally used in thecoatings and adhesives & sealant industries.

Therefore, there is a need to produce a water-soluble epoxy silaneoligomer that is useful in a waterborne system. There is also a need foran epoxy silane oligomer structure having epoxy functional groups to beused in water borne systems for corrosion protection, zinc rich primers,shop primers, metallic pigment dispersions or other coatingapplications.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with the present invention, a process for producing anepoxy silane oligomer is provided that comprises reacting glycidoxysilane and/or cycloaliphatic epoxy silane having 2 or 3 alkoxy groupsand, optionally, a copolymerizable silane other than glycidoxy silaneand cycloaliphatic epoxy silane, with less than 1.5 equivalents of waterin the presence of a catalyst, wherein said water is continuously fedduring the reaction.

Further in accordance with the present invention, a coating compositionis provided which contains epoxy silane oligomer made by the aforesaidprocess.

Unlike epoxy silane oligomers described in U.S. Pat. No. 6,391,999 whichare not readily water soluble, the epoxy silane oligomers made by theprocess of the invention exhibit good water solubility making themparticularly useful as components of water-based and waterbornecoatings.

Various other features, aspects, and advantages of the present inventionwill become more apparent with reference to the following descriptionand appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram describing a process for forming paint inaccordance with the prior art.

FIG. 2 is a flow diagram describing a process for forming paint inaccordance with an embodiment of the present invention.

FIG. 3 is a flow diagram describing a process for forming paint inaccordance with another embodiment of the present invention.

FIG. 4 is a flow diagram describing a process for forming paint inaccordance with yet another embodiment of the present invention.

FIG. 5 is a flow diagram describing a process for forming paint inaccordance with still another embodiment of the present invention.

FIG. 6 is a flow diagram describing a process for forming a metal pastein accordance with another embodiment of the present invention.

FIG. 7 is a flow diagram describing a process for forming a protectivecoating in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Epoxy silane oligomer synthesized with glycidoxy silane and/orcycloaliphatic epoxy silane having 2 or 3 alkoxy groups, optionally,with a copolymerizable silane other than glycidoxy silane andcycloaliphatic epoxy silane, with less than 1.5 equivalents of water inthe presence of a catalyst, wherein said water is continuously fedduring the reaction.

According to an embodiment of the present invention, an epoxy silaneoligomer is synthesized using controlled hydrolysis and condensation ofan epoxy silane monomer with continuous water introduction and a strongcationic exchange resin as a catalyst. The epoxy silane monomer may beeither a glycidoxy or cycloaliphatic epoxy silane having 2 or 3functional alkoxy groups.

According to another embodiment of the present invention, the epoxysilane monomers may be based on glycidoxy epoxy silanes orcycloaliphatic epoxysilanes in combination with other monomeric silanesthat can provide specific organofunctional features like vinyl,methacryl, alkyl, polyalkyleneoxide and others with the proviso thatthey don't interact with epoxy functionalities.

According to another embodiment of the present invention, the epoxysilane monomer is combined with a polyalkyleneoxide functional silane,the latter improving the water solubility and the stability of theoligomer of the two silanes. Other monomeric silanes, as referenced inU.S. Pat. Nos. 3,337,496, 3,341,469 and 5,073,195 which are incorporatedherein by reference, can be added to improve the solubility andstability of epoxy silane oligomers.

According to another embodiment of the present invention, the glycidoxysilane can be one or more of gamma-glycidoxypropyl trimethoxysilane,gamma-glycidoxypropyl triethoxysilane, gamma-glycidoxypropylmethyldimethoxysilane, gamma-glycidoxypropyl methyldiethoxysilane andthe like.

According to another embodiment of the present invention, thecycloaliphatic expoxy silane can be one or more ofbeta-(3,4-expoxycyclohexyl)-ethyl trimethoxysilane,beta-(3,4-expoxycyclohexyl)-ethyl methyl dimethoxysilane,beta-(3,4-expoxycyclohexyl)-ethyl methyl diethoxysilane,beta-(3,4-epoxycyclohexyl)-ethyl triethoxysilane and the like.

The catalyst can be an ion exchange resin such as Purolite® CT-175 or CT275 available from Plurolite, Amberlite® IRA 400, 402, 904, 910 or 966available from Rohm & Haas, Lewatit® M-500, M-504, M-600, M-500-A, M-500or K-2641, available from Bayer, Dowex® SBR, SBR-P, SAR, MSA-1 or MSA 2,available from Dow, or DIAON® SA10, SA12, SA 20A, PA-302, PA-312, PA-412or PA-308, available from Mitsubishi. The catalyst can also be analkylammonium salt such as hexadecyltrimethylammonium chloride,tetra-n-butylammonium chloride, or benzyl trimethyl ammonium chloride orbromide or the hydroxide form of these alkylammonium salts either aloneor in combination with the halide salts. Also useful as catalysts arethe reaction products of quaternary ammonium organofunctional silanesand supports such as ceramic (inclusive of glass), silica gel,precipitated or fumed silica, alumina, aluminosilicate, etc.

According to another embodiment of the present invention, the molarratio of water to silane monomer(s) is from about 0.1 to about 1.5.According to yet another embodiment of the present invention, the molarratio of water to silane monomer(s) is from about 0.4 to about 1.0.According to still yet another embodiment of the present invention, themolar ratio of water to silane monomer(s) is less than about 0.5.

According to another embodiment of the present invention, the epoxysilane oligomer (ESO) is synthesized in the presence of an alcohol-free,chemically stable solvent, e.g., an aliphatic hydrocarbon, a paraffinsuch as naphtha or mineral spirits, an aromatic hydrocarbon such astoluene, xylene or higher boiling homolog thereof; a ketone such asacetone, methyl ethyl ketone, methyl iso-butyl ketone, amyl ketone, anester such as ethyl, n-propyl, n-butyl or amyl acetate, and the like.

In another embodiment of the present invention, by-product alcohol iscontinuously removed during the reaction.

According to yet another embodiment of the present invention, awaterborne coating composition is provided which comprises a particulatemetal; a surfactant; an epoxy silane oligomer produced in accordancewith the invention; and, one or more optional ingredients selected fromthe group consisting of pH adjusting agent, cosolvent and epoxy silanemonomer.

According to another embodiment of the present invention, the waterbornecoating composition includes the particulate metal in an amount of fromabout 0.1 to about 80 weight percent, the surfactant in an amount offrom about 0.05 to about 10 weight percent, the epoxy silane oligomer inan amount of from about 0.1 to about 30 weight percent, water in anamount of from about 5 to about 99 weight percent, optional pH adjustingagent, where present, in an amount sufficient to provide a pH of fromabout 4 to about 6, optional cosolvent, where present, in an amount offrom about 0.1 to about 60 weight percent, and optional silane monomer,where present, in an amount of up to about 10 weight percent.

For the purpose of aiding the dispersing of the ESO which is made inaccordance with the process of the present invention in a waterbornesystem, a pH-adjusting agent is added during the dispersion of the ESOsin a waterborne system. The pH may be adjusted between 4 to 6. ThepH-adjusting agent may be boric acid. According to another embodiment ofthe present invention, the pH adjusting agent is orthophosphoric acid,acetic acid or citric acid or any other acids that would have nodetrimental effects to corrosion protection.

According to another embodiment of the present invention, co-solventsare added during the dispersion of the ESO in a waterborne system. Theco-solvent may be dipropylene glycol methyl ether (e.g., Dowanol® DPMavailable from Dow Chemical) or other glycol ethers as well as alcohols.

According to another embodiment of the present invention, a combinationof the pH adjusting agent and co-solvent is added during the dispersionof the ESO in the formulation of a waterborne system.

According to another embodiment of the present invention, a surfactantis added during the dispersion of the ESO in a waterborne system. Thesurfactant may be either an alkyl-phenol-ethoxylate (APEO) surfactant oran APEO free surfactant. According to another embodiment of the presentinvention, the surfactant is a cationic, anionic or non-ionicsurfactant, or a polyether siloxane-based surfactant or any combinationthereof. According to yet another embodiment of the present invention, asurfactant having a hydrophilic-lipophilic balance (HLB) of 13 is used.According to another embodiment of the present invention, the surfactantcan be a package of several surfactants with different HLB valuesranging from about 5 to about 15 or a package of non-ionic surfactantincluding a siloxane surfactant.

According to another embodiment of the present invention, the ESOs areused in water borne zinc rich primers or protective coating systems,metallic pigment paste dispersions, a blend of metallic paste dispersionwith water borne latexes or dispersions for primers, coatings or inks,waterborne protective coatings, waterborne shop primers, metallicpigment dispersions and their use in printing ink or coatings, crosslinkers of water borne latexes and dispersions including but not limitedto anionic and cationic dispersions, acrylic styrene acrylic,polyurethane and epoxy dispersions, vinyl resins, adhesion promoters forsame systems described above, additive or binder systems for dispersionof metallic fillers and pigments, pigment dispersion for inorganicfillers such as calcium carbonate, kaolin, clay, etc., waterborneprotective coatings using zinc and other metallic pigments assacrificial pigment, waterborne decorative paints for metal, plasticsand other substrates.

According to another embodiment of the present invention, a waterbornecoating composition is provided that includes water in an amount fromabout 5 to about 99 weight percent of the solvent content, a particulatemetal, a surfactant and an aqueous medium including an epoxy silaneoligomer and water, wherein the epoxy silane oligomer is produced byreacting either a glycidoxy or cycloaliphatic epoxy silane having 2 or 3alkoxy groups with less than 1.5 equivalents of water in the presence ofa catalyst resin, wherein the water is continuously fed during thereaction, and separating the catalyst resin from the epoxy silaneoligomer.

The waterborne coating may also include an epoxy silane monomer and/oran additional epoxy silane oligomer. The additional epoxy silane monomermay be gamma-glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyltriethoxysilane, gamma-glycidoxypropyl methyldimethoxysilane and agamma-glycidoxypropyl methyldiethoxysilane. The additional epoxy silaneoligomer may be the same as the epoxy silane oligomer used at thedispersion stage or an ESO formed from a different starting epoxy silanemonomer or water to silane ratio.

In addition to an epoxy silane oligomer produced in accordance with thepresent invention and a monomeric epoxy silane, the waterborne coatingcomposition may include an epoxy silane monomer and/or a non-epoxy basedmonomeric silane such as a vinyl silane, an alkyl silane or an alkylenesilane. Typical non-epoxy based monomeric silanes may bevinyltrimethoxysilane (e.g., Silquest® A-171 available from GESilicones), vinyltriethoxysilane (e.g., Silquest® A-151 available fromGE Silicones), vinylmethyldimethoxysilane (e.g., Silquest® A-2171available from GE Silicones), vinyltriisopropoxysilane (e.g., CoatOSil®1706 available from GE Silicones), n-octyltriethoxy silane (e.g.,Silquest® A-137 available from GE Silicones), propyltriethoxy silane(e.g., Silquest® A-138 available from GE Silicones),propyltrimethoxysilane, methyltrimethoxysilane (e.g., Silquest® A-1630available from GE Silicones), methyltriethoxysilane (e.g., Silquest®A-162 available from GE Silicones), polyalkyleneoxidetrimethoxysilane(e.g., Silquest® A-1230 available from GE Silicones),3-methacryloxypropyltrimethoxy silane (e.g., Silquest® A-174 availablefrom GE Silicones), 3-methacryloxypropyltriethoxy silane (e.g.,Silquest® Y-9936 available from GE Silicones) or3-methacryloxypropyltriisopropoxy silane (e.g., CoatOSil® 1757 availablefrom GE Silicones).

The aqueous medium of the waterborne coating may include a pH agent. ThepH-adjusting agent may be, but is not limited to, boric acid,orthophosphoric acid, acetic acid, glycolic, malic acid, citric acid orother carboxylic acids. In addition, according to an embodiment of thepresent invention, the pH-adjusting agent is present in an amountranging of from about 0.5 to about 4.0 weight percent of the aqueousmedium.

The aqueous medium of the waterborne coating may include a cosolvent.The cosolvent may be dipropylene glycol methyl ether. Other solvents mayinclude one or combinations of glycol ether solvents or the like.According to another embodiment, the cosolvent is ethylene glycolmonomethyl ether (EGME), ethylene glycol monoethyl ether (EGEE),ethylene glycol monopropyl ether (EGPE), ethylene glycol monobutyl ether(EGBE), ethylene glycol monomethyl ether acetate (EGMEA), ethyleneglycol monohexyl ether (EGHE), ethylene glycol mono-2-ethylhexyl ether(EGEEHE), ethylene glycol monophenyl ether (EGPhE), diethylene glycolmonomethyl ether (diEGME), diethylene glycol monoethyl ether (diEGEE),diethylene glycol monopropyl ether (diEGPE), diethylene glycol monobutylether (diEGBE), butyl carbitol, dipropylene glycol dimethyl ether(diEGME), butyl glycol, butyldiglycol or ester-based solvents. Accordingto another embodiment, the ester-based solvents include ethylene glycolmonobutyl ether acetate (EGEEA), diethylene glycol monoethyl etheracetate (diEGEEA), diethylene glycol monobutyl ether acetate (diEGBEA),n-propyl acetate, n-butyl acetate, isobutyl acetate,methoxypropylacetate, butyl cellosolve actetate, butylcarbitol acetate,propylene glycol n-butyl ether acetate, t-Butyl acetate or analcohol-based solvent. According to yet another embodiment, thealcohol-based solvent may be n-butanol, n-propanol, isopropanol orethanol.

According to another embodiment of the present invention, the cosolventis present in an amount ranging of from about 0.1 to about 60 weightpercent of the aqueous medium.

According to another embodiment of the present invention, the aqueousmedium includes an epoxy silane monomer. The epoxy silane monomer may begamma-glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyltriethoxysilane, gamma-glycidoxypropyl methyldimethoxysilane orgamma-glycidoxypropyl methyldiethoxysilane.

The aqueous medium of the waterborne coating may include a surfactant.The surfactant may be an alkyl-phenol-ethoxylate surfactant, a cationicsurfactant, anionic surfactant, a non-ionic surfactant, or a polyethersiloxane based surfactant or any combination thereof. According to anembodiment of the present invention, the surfactant has ahydrophilic-lipophilic balance (HLB) ranging from about 5 to about 13.According to another embodiment of the present invention, the aqueousmedium includes two or more surfactants, wherein each of the surfactantsindependently has an HLB value ranging from about 5 to about 15. Inaddition, the surfactant may be present in an amount ranging of fromabout 3 to about 6 weight percent of the aqueous medium. According toyet another embodiment of the present invention, the aqueous medium ofthe waterborne coating includes a surfactant and a pH-adjusting agent.

The particulate metal of the coating composition may, in general, be anymetallic pigment such as finely divided aluminum, manganese, cadmium,nickel, stainless steel, tin, ferroalloys, magnesium or zinc. Accordingto another embodiment of the present invention, the particulate metal iszinc dust or zinc flake or aluminum dust or aluminum flake in a powderor paste dispersion form. The particulate metal may be a mixture of anyof the foregoing, as well as comprise alloys and intermetallic mixturesthereof. Flake may be blended with pulverulent metal powder, buttypically with only minor amounts of powder. The metallic powderstypically have particle size such that all particles pass 100 mesh and amajor amount pass 325 mesh (“mesh” as used herein is U.S. Standard SieveSeries). The powders are generally spherical as opposed to the leafingcharacteristic of the flake.

According to another embodiment of the present invention, the metalparticulate is a combination of aluminum and zinc. Where the metalparticulate is the combination of zinc with aluminum, the aluminum maybe present in very minor amount, e.g., from as little as about 2 toabout 5 weight percent, of the particulate metal, and still provide acoating of bright appearance. Usually the aluminum will contribute atleast about 10 weight percent of the particulate metal. Thus,frequently, the weight ratio of aluminum to zinc in such a combinationis at least about 1:9. On the other hand, for economy, the aluminum willadvantageously not contribute more than about 50 weight percent of thezinc and aluminum total, so that the aluminum to zinc weight ratio canreach 1:1. The particulate metal content of the coating composition willnot exceed more than about 35 weight percent of the total compositionweight to maintain best coating appearance, but will usually contributeat least about 10 weight percent to consistently achieve a desirablebright coating appearance. Advantageously, where aluminum is present,and especially where it is present without other particulate metal, thealuminum will provide from about 1.5 to about 35 weight percent of thetotal composition weight. Typically, when particulate zinc is present inthe composition, it will provide from about 10 to about 35 weightpercent of the total composition weight. The metal may contribute aminor amount of liquid, e.g., dipropylene glycol or mineral spirits.Particulate metals contributing liquid are usually utilized as pastes,and these pastes can be used directly with other compositioningredients. However, it is to be understood that the particulate metalsmay also be employed in dry form in the coating composition.

For the purpose of aiding the dispersion of the particulate metal, adispersing agent may be added, i.e., surfactant, serving as a “wettingagent” or “wetter”, as such terms are used herein. Suitable such wettingagents or mixture of wetting agents can include nonionic agents such asthe nonionic alkylphenol polyethoxy adducts, for example. Also, therecan be used anionic wetting agents, and these are most advantageouslycontrolled foam anionic wetting agents. These wetting agents or mixtureof wetting agents can include anionic agents such as organic phosphateesters, as well as the diester sulfosuccinates as represented by sodiumbistridecyl sulfosuccinate. The amount of such wetting agent istypically present in an amount from about 0.01 to about 3 weight percentof the total coating composition.

It is contemplated that the composition may contain a pH modifier, whichis able to adjust the pH of the final composition. Usually, thecomposition, without pH modifier, will be at a pH within the range offrom about 6 to about 7.5. It will be understood that as the coatingcomposition is produced, particularly at one or more stages where thecomposition has some, but less than all, of the ingredients, the pH at aparticular stage may be below 6. However, when the complete coatingcomposition is produced, and especially after it is aged, which agingwill be discussed herein below, then the composition will achieve therequisite pH. Where a modifier is used, the pH modifier is generallyselected from the oxides and hydroxides of alkali metals, with lithiumand sodium as the preferred alkali metals for enhanced coatingintegrity; or, it is selected from the oxides and hydroxides usually ofthe metals belonging to the Groups IIA and IIB in the Periodic Table,which compounds are soluble in aqueous solution, such as compounds ofstrontium, calcium, barium, magnesium, zinc and cadmium. The pH modifiermay also be another compound, e.g., a carbonate or nitrate, of theforegoing metals.

According to another embodiment of the present invention, the coatingcomposition may also contain what is usually referred to herein as a“boric acid component”, or “boron-containing compound”. For the“component” or for the “compound”, as the terms are used herein, it isconvenient to use orthoboric acid, commercially available as “boricacid”, although it is also possible to use various products obtained byheating and dehydrating orthoboric acid, such as metaboric acid,tetraboric acid and boron oxide.

The coating composition may also contain thickener. It had previouslybeen considered that thickener was an important ingredient, as discussedin U.S. Pat. No. 5,868,819. It has, however, now been found thatserviceable coating compositions can be produced which do not containthickener, and desirable coating composition characteristics such asstorage stability can nevertheless be achieved. For the presentinvention, the thickener is thus an optional substituent. The thickener,when present, can contribute an amount of between about 0.01 to about2.0 weight percent of the total composition weight. This thickener canbe a water soluble cellulose ether, including the “Cellosize”(trademark) thickeners. Suitable thickeners include the ethers ofhydroxyethylcellulose, methylcellulose, methylhydroxypropylcellulose,ethylhydroxyethylcellulose, methylethylcellulose or mixtures of thesesubstances. Although the cellulose ether needs to be water soluble toaugment thickening of the coating composition, it need not be soluble inthe organic liquid. When thickener is present, less than about 0.02weight percent of the thickener will be insufficient for impartingadvantageous composition thickness, while greater than about 2 weightpercent of thickener in the composition can lead to elevated viscositieswhich provide compositions that are difficult to work with. According toan embodiment of the present invention, for thickening withoutdeleterious elevated viscosity, the total composition will contain fromabout 0.1 to about 1.2 weight percent of thickener. It will beunderstood that although the use of a cellulosic thickener iscontemplated, and thus the thickener may be referred to herein ascellulosic thickener, some to all of the thickener may be anotherthickener ingredient. Such other thickening agents include xanthan gum,associative thickeners, such as the urethane associative thickeners andurethane-free nonionic associative thickeners, which are typicallyopaque, high-boiling liquids, e.g., boiling above 100° C. Other suitablethickeners include modified clays such as highly beneficiated hectoriteclay and organically modified and activated smectite clay. Whenthickener is used, it is usually the last ingredient added to theformulation.

The coating composition may contain further additional ingredients inaddition to those already enumerated hereinabove. These otheringredients may include phosphates. It is to be understood thatphosphorous-containing substituents, even in slightly soluble orinsoluble form, may be present, e.g., as a pigment such as ferrophos.The additional ingredients will frequently be substances that caninclude inorganic salts, often employed in the metal coating art forimparting some corrosion-resistance or enhancement incorrosion-resistance. Materials include calcium nitrate, dibasicammonium phosphate, calcium sulfonate, 1-nitropropane lithium carbonate(also useful as a pH modifier), or the like, and, if used, these aremost usually employed in the coating composition in a total combinedamount of from about 0.1 to about 2 weight percent. Greater than about 2weight percent of such additional ingredient may be utilized where it ispresent for a combination of uses, such as lithium carbonate used as acorrosion-inhibitor and also as a pH adjusting agent. Most usually thecoating composition is free from these further additional ingredients.

In an other embodiment of the present invention, the formulation mayinclude, when necessary, a surface active agent for reducing foam oraiding in de-aeration. The de-foamer and de-aerator agent may includemineral oil based material, silicone-based material, a polyethersiloxane or any combination thereof. The concentration of the surfaceactive agents can be adjusted to in the range from about 0.01% to about5% of active material. The surface active agents may be used as a purematerial or as a dispersion in water or any other appropriate solvent todisperse them into the final waterborne composition.

The coating composition may also contain surface effect agents formodifying a surface of the coating composition such as increased marresistance, reduced coefficient of friction, flatting effects, improvedabrasion resistance. Examples may include silicone polyether copolymerssuch as e.g., Silwet® L-7608 and other variants available from GESilicones

The additives discussed above can be added at any stage of the use of anESO produced in accordance with the present or in any of the differentsteps of the production of a waterborne composition produced inaccordance with the present invention.

The coating formulation may also contain corrosion inhibitors. Examplesof inhibitors may include chromate, nitrite and nitrate, phosphate,tungstate and molybdate, or organic inhibitors include sodium benzoateor ethanolamine.

According to another embodiment of the present invention, theformulations discussed herein using an ESO of the present invention maybe chrome-free. According to another embodiment of the presentinvention, it may be desirable to prepare a chrome-containingformulation using an ESO of the present invention. Suchchrome-containing anti-corrosion pigments are for example zinc chromateslike zinc potassium chromates and zinc tetrahydroxychromates. Otheranti-corrosive pigments may include molybdates, wolframates, zirconates,vanadates, zinc phosphates, chromium phosphates, aluminum triphosphates,barium phosphates, and aluminum zinc phosphates. Such anti-corrosivepigments may also be combined with an organic corrosion inhibitor likezinc salt, e.g., 5-nitrophtalic acid.

The coating composition can be formulated in a variety of procedures.For example, as an alternative to directly using the ESO, in accordancewith the present invention above, the ESO may used as a binding agent ina concentrated form or as a more dilute premixture of the ESO, such asthe ESO is mixed with a diluent. The diluent may be selected from thesubstituents providing the coating composition liquid medium, such aswater, or water plus boric acid component, or water plus low-boilingorganic liquid including acetone. Additionally, it is contemplated thatthe ESO binding agent may initially be mixed together with any of theother necessary composition ingredients. Hence, the ESO in a liquidform, such as in a diluent, may be mixed with other coating compositioningredients which are in solid or liquid form. However, it will mostalways be present in any composition before a particulate metal is addedto that composition.

In addition, the ESOs, in accordance with the present inventiondiscussed above, may be incorporated in many different formulationshaving many different uses such as those described in U.S. Pat. Nos.6,270,884 and 6,656,607, which are incorporated herein by reference intheir entirety.

Packaging concepts, as well as formulation considerations for how thecoating composition is prepared, can be taken into consideration whenbringing composition ingredients together. Thus, it is contemplated thatless than all of the coating composition ingredients may be present inother composition premixtures. Such can include, for example, a wettingagent, or a wetting agent plus a boric acid component, or an aqueousmedium plus a boric acid component. Such premixtures may be made up withliquid which may or may not include the aqueous medium, and may or maynot include an organic liquid.

Even considering storage stability, the composition may be a one-packformulation of all coating composition ingredients or a two-packformulation. It will be understood that the final coating composition,as well as separate pre-blended packages, may be prepared inconcentrated form.

Where particulate aluminum will be used in the coating composition, andespecially where both particulate zinc and particulate aluminum will beemployed, a variant of the above packaging considerations may beutilized. According to another embodiment of the present invention, itis desirable to use a zinc and aluminum combination and to start with amixture, susceptible to packaging, of about 0.1 to 15 percent wettingagent, about 0.1 to 5 percent boric acid component, about 0.5 to 35percent silane binding agent and a balance of aqueous medium to provide100 weight percent total mixture weight. Into this mixture, there thencan be dispersed particulate metal, usually as a flake, e.g., zincflake. Additional aqueous medium may be added, whereby the resultingmetal-containing dispersion can contain about 25 to about 45 weightpercent of the particulate metal and from as much as about 40, up toabout 60, weight percent aqueous medium, both basis the total weight ofthe resulting metal-containing dispersion.

Typically, there is then separately prepared an additional packageprecursor blend to introduce the particulate aluminum into the finalcoating composition. This particulate aluminum will generally bealuminum flake, but it is to be understood that other metals in flakeform, e.g., zinc flake, may be present with the aluminum.

Even when made as a one-package formulation, the final coatingcomposition has highly desirable storage stability. This confirms thebinding ability of the ESOs, in accordance with the present invention,to protect the particulate metal from deleterious reaction with othercomposition ingredients during extended storage. Such extended shelfstability was unexpected, owing to the recognized reaction problems ofparticulate metal in water-reducible systems, e.g., hydrogen gasevolution from aqueous compositions containing particulate zinc.However, even after storage as a single package, compositions of thepresent invention can be unpackaged, prepared for coating application asby brisk stirring, then readily applied. Resulting coatings can have thedesirable corrosion-resistance, and often the other coatingcharacteristics, of coatings applied from freshly prepared compositions.

Where a bath of the coating composition has been prepared, it has beenfound desirable to age this blend. Aging can help provide better coatingperformance. Usually, aging of the blend will be for at least 1 hour,and advantageously for at least about 2 hours to about 7 days, or more.Aging for less than 1 hour can be insufficient for developing desirablebath characteristics, whereas aging for greater than 7 days can beuneconomical.

The final coating composition, whether freshly prepared or afterstorage, may be applied by various techniques, such as immersiontechniques, including dip drain and dip spin procedures. Where parts arecompatible with same, the coating can be applied by curtain coating,brush coating or roller coating and including combinations of theforegoing. It is also contemplated to use spray technique as well ascombinations, e.g., spray and spin and spray and brush techniques.Coated articles that are at an elevated temperature may be coated, oftenwithout extensive cooling, by a procedure such as dip spin, dip drain orspray coat.

The protected substrate can be any substrate, e.g., a ceramic or similarsubstrate, but is most particularly a metal substrate such as a zinc oriron, e.g., steel, substrate, an important consideration being that anysuch substrate withstand the heat curing conditions for the coating. Bya “zinc” substrate it is meant a substrate of zinc or zinc alloy, or ametal such as steel coated with zinc or zinc alloy, as well as asubstrate containing zinc in intermetallic mixture. Likewise, the ironof the substrate can be in alloy or intermetallic mixture form.Especially where such are metal substrates, which are most usuallyferrous substrates, these may be pretreated, e.g., by chromate orphosphate treatment, prior to application of the undercoating. Thus, thesubstrate may be pretreated to have, for example, an iron phosphatecoating in an amount from about 50 to about 100 mg/ft² or a zincphosphate coating in an amount from about 200 to about 2,000 mg/ft².

For the substrates containing applied coating composition, thesubsequent curing of the composition on the substrate will usually be ahot air oven cure, although other curing procedures can be used, e.g.,infrared baking and induction curing. The coating composition will beheat-cured at an elevated temperature, e.g., on the order of about 450°F., but usually greater, oven air temperature. The cure will typicallyprovide a substrate temperature, usually as a peak metal temperature, ofat least about 450° F. oven air temperatures may be more elevated, suchas on the order of 650° F., but for economy, the substrate temperatureneed not exceed about 450° F. Curing, such as in a hot air convectionoven, can be carried on for several minutes. Although cure times may beless than 5 minutes, they are more typically on the order of from about10 to about 40 minutes. It is to be understood that cure times andtemperatures can be effected where more than one coating is applied orwhere a subsequently applied, heat-cured topcoating will be used. Thus,shorter time and lower temperature cures can be employed when there willbe applied one or more additional coatings or a topcoating that proceedsthrough an elevated temperature bake at a longer cure time. Also, wheremore than one coating is applied or a heat-curable topcoating will beapplied, the first coating, or undercoating, may only need be dried, asdiscussed hereinabove. Then, curing can proceed after application of asecond coating, or of a heat-cured topcoating.

The resulting weight of the coating on the metal substrate may vary to aconsiderable degree, but will always be present in an amount supplyinggreater than 500 mg/ft² of coating. A lesser amount will not lead todesirably enhanced corrosion-resistance. Advantageously, a coating ofgreater than about 1,000 mg/ft² of coated substrate will be present forbest corrosion-resistance, while most typically between about 2,000 to5,000 mg/ft² of coating will be present. In this coating, there willgenerally be present from about 400 mg/ft² to about 4,500 mg/ft² ofparticulate metal.

Before use, the coated substrate may be topcoated, e.g., with silicasubstance. The term “silica substance”, as it is used herein for thetopcoating, is intended to include both silicates and colloidal silicas.The colloidal silicas include both those that are solvent-based as wellas aqueous systems, with the water-based colloidal silicas being mostadvantageous for economy. As is typical, such colloidal silicas caninclude additional ingredients, e.g., thickeners as, for example, up toabout 5 weight percent of an above-discussed water-soluble celluloseether. Also, a minor amount, e.g., 20 to 40 percent by weight andusually a lesser amount, of the colloidal silicas can be replaced bycolloidal alumina. In general, the use of colloidal silicas will providefor heavier topcoats of silica substance over undercoated substratematerials. It is contemplated to use colloidal silicas containing up to50 percent by weight solids, but typically, much more concentratedsilicas will be diluted, for example, where spray application of thetopcoat will be used.

When the topcoating silica substance is silicate, it may be organic orinorganic. The useful organic silicates include the alkyl silicates,e.g., ethyl, propyl, butyl and polyethyl silicates, as well as alkoxylsilicates such as ethylene glycol monoethyl silicate. Most generally foreconomy, the organic silicate is ethyl silicate. Advantageously, theinorganic silicates are used for best economy and corrosion-resistanceperformance. These are typically employed as aqueous solutions, butsolvent-based dispersions may also be used. When used herein inreference to silicates, the term “solution” is meant to include truesolutions and hydrosols. The preferred inorganic silicates are theaqueous silicates that are the water-soluble silicates, includingsodium, potassium, lithium and sodium/lithium combinations, as well asother related combinations.

Other ingredients may be present in the silica substance topcoatingcomposition, e.g., wetting agents and colorants, and the composition maycontain chrome substituents if desired, but can be chrome-free asdefined hereinabove to provide a totally chrome-free coating. Substancesthat may be present can further include thickening and dispersing agentsas well as pH adjusting agents, but all such ingredients will typicallynot aggregate more than about 5 weight percent, and usually less, of thetopcoating composition so as to provide for enhanced coating compositionstability coupled with augmented coating integrity. The silica substancetopcoating may be applied by any of the above described varioustechniques for use with the coating composition, such as immersiontechniques including dip drain and dip spin procedures.

By any coating procedure, the topcoat should be present in an amountabove about 50 mg/ft² of coated substrate. For economy, topcoat weightsfor cured topcoating will not exceed about 2,000 mg/ft² of coatedsubstrate. This range is for the cured silica substance topcoating.Preferably, for best coating efficiency and silica substance topcoateconomy, the topcoat is an inorganic silicate providing from about 200to about 800 mg/ft² of cured silicate topcoating.

For the silica substance topcoat curing, it is typical to select thecuring conditions in accordance with the particular silica substanceused. For the colloidal silicas, air drying may be sufficient; but, forefficiency, elevated temperature curing is preferred for all the silicasubstances. The elevated temperature curing can be preceded by drying,such as air drying. Regardless of prior drying, a lower curetemperature, e.g., on the order of about 150° F. to about 300° F., willbe useful for the colloidal silicas and organic silicates. For theinorganic silicates, curing typically takes place at a temperature onthe order of about 300° F. to about 500° F. In general, curetemperatures on the order of from about 150° F. to about 800° F. ormore, as peak metal temperatures, may be useful. At the more elevatedtemperatures, cure times may be as fast as about 10 minutes, althoughlonger cure times, up to about 20 minutes, are more usual. Also,articles can be topcoated with the silica substance topcoat while thearticles are at elevated temperature, as from the curing of thewater-reducible coating composition. Such could be done as by spray coator dip drain, i.e., a dipping of the elevated temperature article intothe topcoat composition, which can provide a quenching of the article.Upon removal from the topcoating composition, the article can bedrained. Some to all of the topcoat curing can be achieved by theoperation.

Before use, the coated substrate with the coating from thewater-reducible coating composition may also be further topcoated withany other suitable topcoating, i.e., a paint or primer, includingelectrocoating primers and weldable primers, such as the zinc-richprimers that may be typically applied before electrical-resistancewelding. For example, it has already been shown in U.S. Pat. No.3,671,331 that a primer topcoating containing a particulate,electrically conductive pigment, such as zinc, is highly serviceable fora metal substrate that is first coated with another coating composition.Other topcoating paints may contain pigment in a binder or can beunpigmented, e.g., generally cellulose lacquers, resin varnishes, andoleoresinous varnishes, as for example tung oil varnish. The paints canbe solvent-reduced or they may be water-reduced, e.g., latex orwater-soluble resins, including modified or soluble alkyds, or thepaints can have reactive solvents such as in the polyesters orpolyurethanes. Additional suitable paints which can be used include oilpaints, including phenolic resin paints, solvent-reduced alkyds,epoxies, acrylics, vinyl, including polyvinyl butyral, and oil-wax-typecoatings such as linseed oil-paraffin wax paints.

Of special interest, the coated substrate with the coating from thewater-reducible coating composition can form a particularly suitablesubstrate for paint deposition by electrocoating. The electrodepositionof film-forming materials is well known and can include electrocoatingof simply a film-forming material in a bath or such a bath which maycontain one or more pigments, metallic particles, drying oils, dyes,extenders, and the like, and the bath may be a dispersion or ostensiblesolution and the like. Some of the well known resinous materials usefulas film-forming materials include the polyester resins, alkyd resins,acrylate resins, hydrocarbon resins, and epoxy resins, and suchmaterials can be reacted with other organic monomers and/or polymersincluding hydrocarbons such as ethylene glycol, monohydric alcohols,ethers, and ketones.

For this, it has also been taught, for example in U.S. Pat. No.4,555,445, that suitable topcoating compositions may be pigmenteddispersions or emulsions. These can include copolymer dispersions inliquid medium as well as aqueous emulsions and dispersions of suitablewaxes. Articles can be topcoated in these compositions, which articlesare at elevated temperature such as after curing of the appliedwater-reducible coating, by procedures including a dip-drain or a spraycoating operation. By such quench coating operation, all of thetopcoating curing may be achieved without further heating. Quenchcoating with polymeric solutions, emulsions and dispersions, and withheated baths, has also been discussed in U.S. Pat. No. 5,283,280.

Before coating, it is in most cases advisable to remove foreign matterfrom the substrate surface, as by thoroughly cleaning and degreasing.Degreasing may be accomplished with known agents, for instance, withagents containing sodium metasilicate, caustic soda, carbontetrachloride, trichlorethylene, and the like. Commercial alkalinecleaning compositions which combine washing and mild abrasive treatmentscan be employed for cleaning, e.g., an aqueous trisodiumphosphate-sodium hydroxide cleaning solution. In addition to cleaning,the substrate may undergo cleaning plus etching, or cleaning plus shotblasting.

The following examples are illustrative of the present invention and theresults obtained by the test procedures. It is to be understood theexamples are not intended, nor should they be construed, as beinglimiting upon the scope of the invention. A person skilled in theapplicable arts will appreciate from these examples that this inventioncan be embodied in many different forms other than as is specificallydisclosed.

EXAMPLE 1 Synthesis Procedures for the Preparation of Epoxy SilaneOligomers

ESO Example 1 was prepared using the procedure outlined in U.S. Pat. No.6,391,999.

ESO Examples 2 through 9 were prepared using the following procedures. Areactor was pre-charged with an epoxy silane and solvent. Then, acationic exchange resin was introduced, and the total charge pre-heatedto reflux. Next, water was introduced slowly, drop-by-drop, using aseparate funnel at the reflux temperature. Introduction times werevaried from 1 to 2 hours. Different reaction times at atmosphericpressure were applied, e.g., from 25 minutes to 2.5 hours. Distillationwas ran immediately after the reaction time to remove the solvent usingvacuum from atmospheric pressure down to −0.2 bars.

More particularly, a 2-liter reactor with a heating envelope wasequipped with mechanical agitation, an introduction funnel and a watercondenser for solvent reflux. The reactor was then charged with a silaneof the type and quantity listed in Table 1, a solvent of the type andquantity listed in Table 1 and a catalyst resin of the type and quantityas listed in Table 1.

The mixture was then heated to reflux, to a temperature ranging of fromabout 70 to about 73° C. The separation introduction funnel was chargedwith distilled water of the quantity listed in Table 1. Next, water wasintroduced drop by drop while stirring with the mechanical agitator fordifferent times (See Table 1).

After complete water introduction, the reaction was left for differentpost reaction times (See Table 1). Next, the condenser was set up as adistillation condenser and equipped with a round flask collector.Solvents were extracted either at atmospheric pressure or under vacuumfor appropriate times so that all solvents were evaporated at reactortemperature and final vacuum of −0.2 bars. The reactor was allowed tocool to room temperature before the product was extracted and filteredthrough filter paper followed by a sintered glass filter number 3. Thedescriptions and amounts of each example are listed in Table 1.

TABLE 1 ESO Example Number ESO Example 1 ESO Example 2 ESO Example 3 ESOExample 4 ESO Example 5 ESO Example 6 Silane Type Gamma- Gamma- Gamma-Gamma- Gamma- Gamma- glycidoxypropyl glycidoxypropyl glycidoxypropylglycidoxypropyl glycidoxypropyl glycidoxypropyl trimethoxysilanetrimethoxysilane trimethoxysilane trimethoxysilane trimethoxysilanetrimethoxysilane (Silquest ® A- (Silquest ® A- (Silquest ® A-(Silquest ® A- (Silquest ® A-187 (Silquest ® A-187 187 available 187available 187 available 187 available available from GE available fromGE from GE from GE from GE from GE Silicones) Silicones) Silicones)Silicones) Silicones) Silicones) Weights 246.4 739.2 739.2 1418.4 1478.41478.4 (grams) Moles 1.04 3.13 3.13 6.00 6.25 6.25 Solvent TypeIsopropyl Acetone Acetone Acetone Acetone Acetone Alcohol Weight 50 125130 250 250 250 (grams) Ion Weight 8 24 24 48 48 48 Exchange (grams)Resin (Amberlite ® IRA 402 CL available from Rohm and Haas) DistilledWeight 27 27 54 108 54 54 Water (grams) Moles 1.5 1.5 3 6 3 3 OperationsIntroduction 0 60 60 130 105 70 Time (minutes) Post 300 150 60 25 45 80Reaction Time (minutes) Distillation 30 120 210 65 20 20 Time (minutes)Total 330 330 330 220 170 170 Reaction Time (minutes) Water/Silane MoleRatio 1.44 0.48 0.96 1.00 0.48 0.48 Character- Residual 15.9 23.5 12.516 22 15 ization Monomer (wt. percent) Epoxy 21.9 20.9 21.6 21.5 21.621.5 content (wt. percent in the neat product) Epoxy 26.0 27.3 24.7 25.627.6 25.3 content (wt. percent in the oligomer portion) Viscosity 689 8649 23 23 23 (mPa · s LV2-30) Product Weight 131.3 630 614 1188 1267 1246Recovered (grams) Weight Loss grams n.a. 109.2 125.2 230.4 211.4 232.4ESO Example Number ESO Example 7 ESO Example 8 ESO Example 9 Silane TypeGamma-glycidoxypropyl Gamma- Gamma- triethoxy silane glycidoxypropylglycidoxypropyl (Silquest ® A-15589 trimethoxysilane triethoxy silaneavailable from GE (Silquest ® A-187 (Silquest ® A-1871 Silicones)available from GE available from GE Silicones) Silicones) + Alkyleneoxidetrimethoxy silane (Silquest ® A-1230 available form GE Silicones)Weights (grams) 870.8 1478.4 A-1871; 472.8 + A-1230; 50.0 Moles 3.136.25 A-1871; 2.0 + A-1230; 0.1 Solvent Type Acetone Ethanol None Weight(grams) 125 360 Ion Weight (grams) 24 48 16 Exchange Resin (Amberlite ®IRA 402 CL available from Rohm and Haas) Distilled Weight (grams) 27 5419 Water Moles 1.5 3 1.1 Operations Introduction Time 60 105 105(minutes) Post Reaction Time 60 125 15 (minutes) Distillation Time 60 1545 (minutes) Total Reaction Time 180 245 265 (minutes) Water/Silane MoleRatio 0.48 0.48 0.5 Characterization Residual Monomer (wt. 98 7.46 n.t.percent) Epoxy content (wt. 15.8 20.9 15.3 percent in the neat product)Epoxy content (wt. n.a. 22.9 n.a. percent in the oligomer portion)Viscosity (mPa · s LV2- 7 cSt 73 7 cSt 30) Product Recovered Weight(grams) 857 1255 483 Weight Loss grams 13.8 223.4 39.8

ESO Example 1 shows that a product using isopropanol as a cosolvent andhaving a high water to silane ratio has a high viscosity. In fact, theproduct of ESO Example 1 has the behavior of silicone oil. Resulting indifficulties with the filtration of the ion exchange resin, lack ofwater dispersibility or solubility and/or poor compatibility withorganic polymers.

ESO Examples 2 through 9 had viscosities ranging from 86 to 23 mPa·s,which were much lower than the viscosity of the ESO Example 1, which hada viscosity of 680 mPa·s.

ESO Example 7 is the only product for which there was no apparentreaction and pure monomer was recovered (95% monomer content for therecovered material and almost identical epoxy content). This can beexplained by the lower hydrolysis rate of the ethoxy groups ofgamma-glycidoxypropyl triethoxy silane as compared to the methoxy groupsof gamma-glycidoxypropyl-trimethyloxysilane of ESO Examples 2 through 6and 8.

Epoxy contents measured on all products, except for ESO Example 7,indicate that epoxy rings are still closed and that a significantoligomerization took place for most products. The mass balances alsoindicate that methanol has been released during the reactions, exceptfor ESO Example 7. Monomeric content of the free epoxy silane monomerleft in the oligomers indicates an incomplete reaction.

Higher water to silane ratios gave higher condensation rates and lowerresidual monomer, as seen in ESO Examples 2, 3, 4, and 5. Theoptimization of the water to silane ratio as well as the curingconditions, even though not completed, help to reduce the monomercontent left into the oligomer. A low monomer content aids in maximizingthe conversion rate and thus to meet the Toronto definition of a polymerand increase the overall performance of the ESO. According to theToronto definition: a “polymer” means a substance consisting ofmolecules characterized by the sequence of one or more types of monomerunits and comprising a simple weight majority of molecules containing atleast three monomer units which are covalently bound to at least oneother monomer unit or other reactant and consists of less than a simpleweight majority of molecules of the same molecular weight. Suchmolecules must be distributed over a range of molecular weights whereindifferences in the molecular weight are primarily attributable todifferences in the number of monomer units. In the context of thisdefinition a “monomer unit” means the reacted form of a monomer in apolymer.

Shorter introduction times combined with longer post reaction timesincreased the conversion rates of ESO Examples 3 and 4 at 12.5 and 16%free monomer, respectively, and ESO Examples 5 and 6 at 22 and 15% freemonomer content, respectively.

The use of an ethanol solvent leads to a higher conversion rate (e.g.,ESO Example 8, which has a free monomer content below 7.5%). However,the ethanol solvents also lead to higher viscosity products, indicatingagain that the choice of alcoholic solvent is critical to maintain lowviscosity products. Further, analysis of the ESO Example 8 shows that acertain extent of trans-esterification took place as illustrated by theGC analysis, as shown in Table 2 below.

TABLE 2 Monomer Content 3-glycidoxypropyl(ethoxydimethoxy)silane 3.32%3-glycidoxypropyltriethoxysilane (equiv. to 0.21% Silquest ® A-1871available from GE Silicones) 3-glycidoxypropyl(diethoxymethoxy)silane 1.4% 3-glycidoxypropyltrimethoxysilane (equiv. to 2.53% Silquest ®A-187 available from GE Silicones) Total monomers 7.46%

The resulting wt. % epoxy of the ESO Example 8 with correction forindividual monomers yields 22.9% significantly lower value than the ESOexamples 2 to 6 based on gamma-glycidoxypropyl trimethoxy silane inacetone. This also indicates that trans-esterification took place inthis example.

ESO Example 9 is a representative example of an epoxy silane co-oligomerbetween gamma-glycidoxy propyl trimethoxy silane (e.g., Silquest® A-187available from GE Silicones) and alkylene oxide tri methoxy silane(e.g., Silquest® A-1230 available from GE Silicones). The wt. % epoxygiven for this material indicates that a portion of the epoxy contenthas been substituted by an ethylene oxide chain, thereby reducing thewt. % epoxy. The weight loss observed during the reaction indicates thatmethanol has been released during the process. The synthesis was runwithout any solvent and analysis of the distillate recovered duringdistillation stage was analyzed as pure methanol.

EXAMPLE 2 Parameters for Water Solubilization of an Epoxy SilaneOligomer

The following examples demonstrate the very satisfactory and superiorresults obtained when the ESOs, in accordance with the presentinvention, are made water-soluble by varying the parameters for watersolubilization in order to use such oligomers in waterborneformulations. The parameters included pH and the influence of solventsand coalescents as well as influence of surfactants.

Procedure of Test:

In a metallic beaker equipped with magnetic stirrer the different ESOprepared according to said procedure were mixed with appropriate solventor surfactant or mixture or both (according to Tables 3 to 6), this inorder to get a homogeneous phase. Then appropriate amounts of water orboric acid solution (according to Tables 3 to 6) are added understirring. Mixture is stirred with magnetic stirrer until complete clearsolution is obtained. Time for completion of such clear solution andfinal pH of solutions were reported.

With respect to ESO Example 1, or the reference ESO, it has beenobserved that except at very high coalescent concentration of Dowanol®DPM, ESO Example 1 is not soluble in water. The level of dipropyleneglycol dimethyl ether Dowanol® DPM or the like required to make ESOExample 1 water-soluble would translate into a very high VOC content,far above acceptable ranges for waterborne coatings (above 45% VOC). Assuch, ESO Example 1 would be too difficult to solubilize and would bemore difficult to use in a waterborne formulation (See Table 3 below fortest results).

TABLE 3 Test Reference Test 1 Test 2 Test 3 Test 4 Test 5 Test 6 EpoxySilane Oligomer 10 10 10 10 10 10 Example 1 (weight percent) Boric Acid(weight percent) 3.9 1.3 2.6 Dipropylene glycol dimethyl 45 30 60 30 30ether (Dowanol ® DPM available from Dow Chemical Company) (weightpercent) H₂O (weight percent) 45 60 30 86.1 58.7 57.4 Appearance Clear 2phases Clear 2 phases 2 phases 2 phases pH 3.69 n.a. 4.09 n.a. n.a. n.a.Time 36 hours Not soluble Immediate Not soluble Not soluble Not solubleafter 1 week after 1 week after 1 week after 1 week

With respect to ESO Example 2, water solubility of the ESO Example 2data showed that fast solubilization could be achieved with lowersolvent content and acidic conditions. In particular, Test 20 is notedas a good compromise in boric acid and Dowanol® DPM contents.

This faster solubilization rate was expected as part of the originaldesign of the oligomer that uses a ratio water to silane of 0.48,leaving some alkoxy groups available for further hydrolysis and alsobecause of lower molecular weight illustrated by lower viscosity of theESO.

TABLE 4 Test Reference Test Test Test Test Test Test Test Test Test TestTest Test Test Test Test Test 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2122 Epoxy silane 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 oligomerexample 2 (wt. percent) Boric Acid 3.9 1.9 1.3 2.6 3.2 1.3 1.1 1.0 2.61.3 Dipropylene 45 30 10 5 60 30 12.5 5 30 60 glycol dimethyl ether(Dowanol ® DPM available from Dow Chemical Company) (wt. percent) H₂O(wt. percent) 90 45 60 80 85 30 86.1 88.1 88.7 87.4 86.8 58.7 76.4 8457.4 28.7 Appearance 2 clear clear clear 2 Clear Clear Clear Clear ClearClear Clear Clear Clear Clear Clear phases phases pH 6.85 3.98 3.67 3.74.05 4.33 4.13 4.84 5.32 4.86 4.33 3.57 3.61 3.74 3.52 4.16 Time time 0time 1 h 18 h time 0 time 0 18 h 96 h 96 h 18 h 18 h 30 min. 18 h 18 h10 min. time 0 0

With respect to ESO Example 3, water solubility of the ESO Example 3 wasprepared with a water to silane ratio 0.96, which had a higher water tosilane ratio as compared to ESO Example 2 having a water to silane ratioof 0.48 tested above. Results, listed in Table 5 below, show that ESOExample 3 is more difficult to solubilize than ESO Example 2. However,with appropriate dispersion times, solubilization could still beachieved after 18 hours. In addition, the higher ratio water to silaneleads to higher condensation rates that make the ESO more hydrophobicand less prone to hydrolysis and solubilization.

TABLE 5 Test Reference Test 23 Test 24 Test 25 Test 26 Test 27 Test 28Test 29 Test 30 Test 31 A-187 9.1 1.3 ESO 9.1 9.1 8.3 7.7 7.8 8.3 9.18.7 Example 3 Water 90.9 90.9 88.7 81.4 75.1 88.7 81.4 87 84.9 BoricAcid 2.2 2 1.8 2.2 2 3.9 2.1 Ethanol 8.3 15.4 Dowanol ® 8.3 DPMDipropylene 4.3 glycol Appearance Clear 2 phases 2 phases 2 phasesWhite- 2 phases Clear 2 phases 2 phases emulsion Time After 1 Hr. NotNot Not Not Not After 18 Hr. Not Not soluble soluble soluble solublesoluble soluble soluble after 1 after 1 after 1 after 1 after 1 after 1after 1 week week week week week week week

EXAMPLE 3 Influence of Wettability of said ESO Structures

The following examples demonstrate the effects of surfactants on theESOs, in accordance with the present invention. The introduction ofspecific surfactants used in the dispersion of metallic powders toimprove wettability of the ESOs was used. More particularly, APEO(alkylphenolethoxylate) surfactants having a HLB of 13.3 and 8.9 wereused in this test (e.g., Berol® 09 and 26 and Berol® 48 available fromAKZO Noble Surface Chemistry, respectively). In addition, an APEO freesurfactant was also compared to Berol® 09.

The following test was used to prepare the examples below. First, apre-blend of surfactant, Dowanol® DPM and ESO Example 2 was prepared.Next, the pre-blend was added into a solution containing water and boricacid. The mixture was then stirred with a magnetic stirrer until acomplete solution was obtained. Results are presented in Table 6 below.

TABLE 6 Test Reference Hydrolysat Hydrolysat Hydrolysat Hydrolysat Test1 Test 2 Test 3 Test 4 ESO Reference ESO ESO ESO ESO Example 2 Example 2Example 2 Example 3 Water, wt. percent 70.2 69.5 71.3 71.3 ESO Quantity,15.4 13.7 14.1 14.1 percent Dowanol ® 12.2 9.9 10.2 10.2 DPM (Availablefrom Dow Chemical), wt. percent Boric Acid, wt. 2.2 0.9 1.2 1.2 percentBerol ® 09 / 3 3.2 3.2 (Available from AKZO Nobel Surface Chemistry),percent Berol ® 26 / 3 / / (Available from AKZO Nobel SurfaceChemistry), wt. percent Solubility time 18 hrs. 4 hrs. 2 hrs. 18 hrs.Appearance Clear Cloudy Clear Clear

Results show that adding an appropriate surfactant can reducedissolution time or reduce the need for cosolvent and/or acid. An APEOsurfactant with an HLB of 13.3 (e.g., Berol® 09) reduces dissolutiontime better than the combination of APEO surfactants with an HLB of 13.3and 9.0.

EXAMPLES 4-17

The following examples are related to coating formulations including theuse of ESOs, in accordance with the present invention, compared withcoating formulations including an epoxy silane monomer. In theseexamples, most of the work was performed using ESO Examples 2, 3, 5 and6. The different procedures used to produce the coatings in Examples4-17 are described in FIGS. 1-5.

Paint Preparation, Application and Testing of Examples 4-17:

All formulations were mixed and dispersed using a Cowles blade disperserwith a blade speed of 10 m/min. Metallic powder dispersion requires hightorque and was run on 250 ml batches in order to optimize the quality ofdispersion.

Stability of the formulations was rated from the hydrogen evolutionresistance of the formulations after appropriate storage times. Allproducts were stored in tightly closed PE containers. Generation of foamat the top of the formulations, which in most cases leads to “slowexpansion” of the containers, was given as a clear sign of hydrogengeneration. Viscosity was adjusted to 20-30 DIN cup number 4 with eitherwater when too high, or HEC (Natrosol® solution available from Hercules)when too low.

Preparation of Test Panels:

Two types of metallic test panels were used. Cold Roll Steel (CRS) andelectrogalvanized panels (EG). The CRS panels were prepared by wipingthe surfaces of the panel with acetone and then ethanol. Next, thesurfaces were brushed with an abrasive/detergent cleaner. Then, thepanels were rinsed under tap water and dried with air dryer beforeapplying the paint. The EG panels were prepared by wiping surfaces withacetone and then ethanol. Next, the panels were immerged in a 1% HNO3solution for 2 minutes. The panels were then rinse under tap water anddried with an air dryer before paint application. All test panels wereused immediately after cleaning.

Paint Application and Baking Conditions:

Paint application was performed using a spray gun in a booth. Paintviscosity was adjusted to about 20 DIN cup number 4 by appropriatedilution with water. One application layer was deposited on a test panelwith target deposition of 20-25 gr./sqm of dry paint. Curing of paintswas performed by air-drying at 70° C. for 20 minutes in an oven followedby baking in an oven at 300° C. for 30 min.

Testing Procedures:

The following test were performed on Examples 4-17: Adhesion test,Cohesion-Metallic Filler Powdering test, Neutral Salt Spray test, andHot Salt Soak test.

The Adhesion test was made directly on the cured panels according to ISO2409-1972. The Cohesion-Metallic Filler Powdering test is the evaluationof cohesion of the metallic powders to bind at the surface of thecoatings once applied and fully cured. This test reflects the filmcohesion and the binding of particles into the film layer. Thecohesion-powdering test is carried out by visual evaluation of thequantity of metallic powder removed by a tape adhesive applied on thesurface coating according to ISO 2409-1972. After the adhesion test, avisual evaluation of the quantity of metallic powder removed by the tapeadhesive applied on the surface coating was made.

High resistance to powdering is noted: Excellent

Medium resistance to powdering is noted: Medium

Low resistance to powdering is noted: Poor

The Neutral Salt Spray test, or salt spray test, is an acceleratedcorrosion test. The purpose of this accelerated corrosion test is toduplicate, in the laboratory, the corrosion performance of a product inthe field. The salt spray test has been used extensively in thisapplication for this purpose. The accelerated corrosion test was runaccording to ISO 7253-1984 with general conditions of tests mentionedhere after as follows:

NaCl solution at 50+/−5 g/l

pH of solution between 6.5 to 7.2

Cabinet temperature 35° C.+/−2° C.

Spray rate over a period of 24 h; 1 to 2 ml/h for an 80 sqm surface.

Plates oriented to the top at 20°+/−5°

Red rust is noticed by visual examination.

The corrosion performance was rated according to the number of hours thesalt solution described above was sprayed on the surface of a paneluntil 5% of the surface was covered with red rust. The performance ofeach of the different coatings was then quoted as the relative hours for5% red rust coverage related to the amount of coating deposited on thetest panel, according to following equation:NSS−Red Rust 5% (hours/g)=Red Rust 5% (hours)/Coatings deposit(g)The corrosion resistance of protected panels is quite often quoted ashours of protection against corrosion per micron of deposit.

The Hot Salt Soak test (HSS) is also an accelerated corrosion test thatwas used for comparison purposes. This test includes immersion of acoating applied on galvanized test panel into a 3% NaCl solution for 5clays at 55° C., which may be equated to a 1000 hour Neutral Salt Spraytest program when applied on some protected coated steel or CRS.

In the HSS test, the test panels are first scratched with two parallelscribes (deep into the base metal) about 10 cm long. After immersion ina Hot Soak bath for a predetermined period of time, the panels werewashed with tap water and observed for red rust appearance as well asthe average creep from scribe. In addition, the NaCl solution wasrefreshed every 2 days in our tests. Performance was rated in a similarway to that of the Neutral Salt Spray test described above. Forinstance, time in hours for 5% and the ratio of hours for the 5%coverage of red rust to appear per the weight of the coating deposit,according to the following equation:HSS−Red Rust 5% (hours/g)=Red Rust 5% (hours)/Coatings deposit(g)

EXAMPLE 4 Using a Monomeric Epoxy Silane of Gamma-GlycidoxypropylTrimethoxy Silane and the Procedure Described in FIG. 1

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were placed in the beaker: 18.92 weight% of demineralized water, 0.58 weight % of boric acid and 9.0 weight %of Silquest® A-187 (available from GE Silicones). The solution was mixedfor 3 hours.

Then, the following ingredients were added while stirring: 33.0 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5 weight% of APEO surfactant (HLB 9—Berol® 26) and 4.8 weight % of Dowanol® DPM,2.0 weight % of additional Silquest® A-187.

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofzinc flake GTT followed by 3.0 weight % aluminum powder Chromal VII.Then, 0.4 weight % of Aerosol® OT75 (available from Cytec) was added tothe final dispersion. During introduction of the components, the speedof the agitator was progressively increased in order to maintainappropriate dispersion torque. Dispersion was maintained for 4 hours.

The final products were then stored for appropriate times (e.g., 2 days,7 days and three months) before post addition of 2.9 weight % ofadditional Silquest® A-187.

The protective coating was then applied on the two test panels (an EGand a CRS test panel as described above). A thin and uniform layer ofpaint was deposited on the test panels using a spray gun. The coatingwas adjusted to about 20 to 25 g/sqm of cured deposit. This adjustmentwas calculated after the baking of the plates. The test plates werebaked according to curing cycle mentioned above. The cured panels werethen tested according to the different procedures described above.Results for Example 4 discussed below.

The Product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 4 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 7.7 hours/g HSS Red Rust 5% 2.9 hours/g

Example 4 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 10.9 hours/g HSS Red Rust 5%  4.2 hours/g

Example 4 On a CRS Test Panel After 3 Months of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Medium NSS Redrust 5% 9.6 hours/g

Example 4 On a EG Test Panel After 7 Days of Aging

Adhesion 3 - partial loss of adhesion Powdering resistance Medium NSSRed rust 5% 24.0 hours/g HSS Red Rust 5% 13.8 hours/g

The corrosion resistance achieved with the monomeric silane (e.g.,Silquest® A-187 available from GE Silicones) using the proceduresdescribed above provided 200 hours of protection on a CRS test panel and480 hours on a EG test panel for 20 g/sqm of coating deposited on thetest panel before more than 5% of the surface of the test panel wascovered by red rust.

Aging of the formulation had limited impact on the performance of thecoating, but the performance was not achieved before several days. Thisparameter is critical in the design of protective coatings as it relatesto induction times in the pot before final performance can be reached.

EXAMPLE 5 Using Monomeric Glycidoxy Propyl Triethyloxy Silane and theProcedure Described in FIG. 1

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were placed into the beaker: 28.92weight % of demineralized water, 0.58 weight % of boric acid, 3.0 weight% of Dowanol® DPM and 3.0 weight % of glycidoxy propyl triethyloxysilane (e.g., Silquest® A-1871 available from GE Silicones). Thesolution was mixed for 3 hours.

Then, the following ingredients were added while stirring: 23.0 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5 weight% of APEO surfactant (HLB 9—Berol® 26), 1.8 weight % of Dowanol® DPM and2.0 weight % of additional Silquest® A-1871, available from GESilicones.

The components were mixed together for ten minutes. Next, metallicfillers were added under agitation: 28.0 weight % of Zinc flake GTTfollowed by 3.0 weight % of Aluminum powder Chromal VII. Finally, 0.4weight % of Aerosol® OT 75 was added to the final dispersion. Duringintroduction, the speed of agitator was progressively increased in orderto maintain an appropriate dispersion torque. Dispersion was maintainedfor 4 hours.

The final products were then stored for 7 days before post addition as atwo pack of 2.9 weight % of additional Silquest® A-1871 was made.Product modified with post addition of Silquest A-1871 was also kept instorage for three months for retesting.

Protective coatings were then applied on two test panels (an EG and aCRS test panel as described above). A thin and uniform layer of paintwas deposited on the test panels using a spray gun. The coating wasadjusted to 20 to 25 g/sqm. This adjustment was calculated after thebaking of the test plates. The test plates were baked according tocuring cycle described above. The cured test panels were then testedaccording to the different procedures described above. Results forExample 5 are indicated below as follows:

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 5 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 8.2 hours/g HSS Red Rust 5% 3.0 hours/g

Example 5 On a CRS Test Panel After 3 Months of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Medium NSS Redrust 5% 10.7 hours/g

Example 5 On a EG Test Panel After 7 Days of Aging

Adhesion 5 - no adhesion Powdering resistance Excellent NSS Red rust 5%24.0 hours/g HSS Red Rust 5% 12.8 hours/g

Corrosion resistance achieved with monomeric silane, e.g., Silquest®A-1871 available from GE Silicones, provided around 200 hours ofprotection on a CRS test panel and 480 hours on a EG test panel for 20g/sqm of coating deposited on the test panel before more than 5% of thesurface of the test panel was covered by red rust.

Aging of the formulation has an impact on the performance of thecoating. The performance of the coating after two days was significantlylower than after aging for 7 days and 3 months.

EXAMPLE 6 Using ESO Example 2 Combined with Glycidoxy Tri Ethoxy Silaneand the Procedure Described in FIG. 2

In this case, the ESO Example 2 was pre-solubilized in water using theformulation described above with respect to Table 4 and combined with atriethoxy epoxy silane as a two-pack system.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were placed in the beaker: 30.92 weight% of demineralized water, 0.58 weight % of boric acid, 4.8 weight % ofDowanol® DPM and 4.25 weight % of ESO Example 2. The solution was mixedfor 18 hours until a clear solution was obtained.

Then, the following ingredients were added while stirring: 21.75 weight% of demineralized water, 0.4 weight % of Hydroxyethylcellulose(Natrosol® HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09)and 1.5 weight % of APEO surfactant (HLB 9—Berol® 26).

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % of Aluminum powder Chromal VII.Finally, 0.4 weight % of Aerosol OT 75 was added to the finaldispersion. During introduction of the components, the speed of theagitator was progressively increased in order to maintain appropriatedispersion torque. Dispersion was maintained for 4 hours.

The final product was then stored for 7 days before post addition as atwo pack of 2.9 weight % of glycidoxy propyl triethoxy silane was added.The product was kept for three months and tested without any furtheraddition of glycidoxy propyl triethoxy silane (e.g., Silquest® A-1871available from GE Silicones) before application.

The Protective coating formed above was then applied on the two testpanels (an EG test panel and a CRS test panel as described above). Athin and uniform layer of was deposited on the test panels. The coatingwas then adjusted to around 20 to 25 g/sqm based on a calculationperformed after baking of the test plates. The substrates were thenbaked according to the curing cycle described above. The cured testpanels were then tested according to the different procedures describedabove. Results for Example 6 discussed below.

The Product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 6 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 8.0 hours/g HSS Red Rust 5% 2.6 hours/g

Example 6 On an EG Test Panel After 7 Days of Aging

Adhesion 1 - little loss of adhesion Powdering resistance Excellent NSSRed rust 5% 25.0 hours/g HSS Red Rust 5% 18.8 hours/g

Corrosion resistance achieved by a combination of the ESO Example 2 withpost addition of glycidoxy propyl triethoxy silane (e.g., Silquest®A-1871) provided around 160 hours of protection on a CRS test panel and500 hours on a EG test panel for 20 g/sqm of coating deposited on thetest panels before more than 5% of the surface of the test panel wouldbe covered by red rust.

This example shows that an Epoxy silane Oligomer used at the dispersionstage of zinc and aluminium powders and combined with an ethoxy basedepoxy silane as a two pack system provide very good stability andcorrosion protection.

EXAMPLE 7 Using ESO Example 2 and the Procedure Described in FIG. 3

In this case, the ESO Example 2 was pre-solubilized in water using theformulation described above with respect to Table 4 and combined with aglycidoxy propyl triethoxy silane (e.g., Silquest® A-1871) during thedispersion stage. No further addition of silane was made afterdispersion.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were placed in the beaker: 33.07 weight% of demineralized water, 0.58 weight % of boric acid, 3.3 weight % ofDowanol® DPM and 4.15 weight % of ESO Example 2. The solution was mixedfor 18 hours until a clear solution was obtained.

Then, the following ingredients were added while stirring: 19.6 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HEIR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5weight % of APEO surfactant (HLB 9—Berol® 26), and additional 3.0 weight% of glycidoxy propyl triethoxy silane (e.g., Silquest® A-1871).

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % of Aluminum powder Chromal VII.Finally, 0.4 weight % of Aerosol® OT 75 was added to the finaldispersion. During introduction of the components, the speed of theagitator was progressively increased in order to maintain appropriatedispersion torque. Dispersion was maintained for 4 hours.

The final product was then stored for 7 days and three months beforeapplication and testing. Application and testing conditions were thesame as those described for Example 4. Results for Example 7 aredescribed below.

The product was stable upon storage and no hydrogen evolution wasobserved, thereby indicating a good protection of metallic particles bysilane coupling.

Example 7 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 10.0 hours/g HSS Red Rust 5%  4.0 hours/g

Example 7 On a CRS Test Panel After 3 Months of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 10.6 hours/g

Example 7 On an EG Test Panel After 7 Days of Aging

Adhesion 1 - little loss of adhesion Powdering resistance Poor NSS Redrust 5% 27.7 hours/g HSS Red Rust 5% 13.8 hours/g

Corrosion resistance achieved by a combination of ESO Example 2 withaddition of Silquest® A-1871 at the dispersion stage provided around 200hours of protection on a CRS test panel and 550 hours on a EG test panelfor 20 grams/sqm of coating deposited on the test panel before more than5% of the surface of the test panel was covered by red rust. Aging ofthe formulation did not affect the performance of the coating.

This example shows that an Epoxy silane Oligomer, in accordance with thepresent invention, combined with an ethoxy based epoxy silane used atthe dispersion stage of zinc and aluminium provide very good stabilityand corrosion protection. The system is in this case is a real one packsystem with excellent durability and outperforms the coatings describedin Examples 4 and 5.

EXAMPLE 8 Using ESO Example 5 and the Procedure Described in FIG. 3

In this example, the ESO Example 2 was pre-solubilized in water usingthe formulation described above with respect to Table 4 and also used atthe dispersion stage.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were placed in the beaker: 18.96 weight% of demineralized water, 0.59 weight % of boric acid, 3.3 weight % ofDowanol® DPM and 4.15 weight % of ESO Example 5. The solution was mixedfor 18 hours until a clear solution was obtained

Then, the following ingredients were added while stirring: 34.2 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5 weight% of APEO surfactant (HLB 9—Berol® 26), and additional 2.5 weight % ofESO Example 5 was added just before dispersion.

The components were mixed together for ten minutes. Next, the followingmetallic fillers were added under agitation: 28.0 weight % of Zinc flakeGTT followed by 3.0 weight % of Aluminum powder Chromal VII. Finally,0.4 weight % of Aerosol® OT 75 was added to the final dispersion. Duringintroduction of the components, the speed of the agitator wasprogressively increased in order to maintain appropriate dispersiontorque. Dispersion was maintained for 4 hours.

The final product was then stored for 7 days and three months beforeapplication and testing. Application and testing conditions are the sameas those described above for Example 4. Results for example 5 arediscussed below.

The product was stable upon storage and no hydrogen evolution wasobserved, thereby indicating a good protection of metallic particles bysilane coupling.

Example 8 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 6.3 hours/g HSS Red Rust 5% 2.5 hours/g

Example 8 On a CRS Test Panel After 3 Months of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 9.8 hours/g

In Example 8 described above, corrosion resistance was achieved by theESO Example 2 as a soluble binder in water and at the dispersion stage,which provided around 130 hours of protection on a CRS test panel after7 days of aging, increasing to 196 hours after 3 months of aging, of 20g/sqm coating deposited on test panel before more than 5% of the surfaceof the test panel was covered by red rust. Aging of the formulationimproved the performance of the coating.

This example illustrates that the use of a pure Epoxy Silane Oligomer,in accordance with the present invention, provides an improvedwaterborne protective coating.

EXAMPLE 9 Using Epoxy Silane Oligomer ESO Example 5 Combined with aVinyl Ethoxy Silane and the Procedure Described in FIG. 3

In this example, the ESO Example 5 was pre-solubilized in water usingthe formulation described above with respect to Table 4 and combinedwith a vinyl triethoxy silane (e.g., Silquest® A-151 available from GESilicones) during the dispersion stage.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added: 18.96 weight % ofdemineralized water, 0.59 weight % of boric acid, 3.3 weight % ofDowanol® DPM and 4.15 weight % of ESO Example 5. The solution was mixedfor 18 hours until clear solution was obtained.

Then, the following ingredients were added while stirring: 34.8 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5 weight% of APEO surfactant (HLB 9—Berol® 26), and additional 1.9 weight % ofvinyl triethoxy silane.

The components were mixed together for ten minutes. Next, the followingmetallic fillers were added under agitation: 28.0 weight % of Zinc flakeGTT followed by 3.0 weight % of Aluminum powder Chromal VII. Finally,0.4 weight % of Aerosol OT 75 was added to the final dispersion. Thefinal product was then stored for 2 and 7 days before application andtesting. Application and testing conditions are the same as thosedescribed above in Example 4. Results for Example 9 are described below.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 9 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 8.9 hours/g HSS Red Rust 5% 3.5 hours/g

Example 9 On a CRS Test Panel After 7 Days of Aging

Adhesion 1 - little loss of adhesion Powdering resistance Poor NSS Redrust 5% 10.4 hours/g HSS Red Rust 5%  2.8 hours/g

Corrosion resistance achieved by a combination of ESO Example 5 withvinyl triethoxy silane (e.g., Silquest® A-151 available from GESilicones) at the dispersion stage, which provided about 180 hours ofprotection on a CRS test panel after 2 days of aging, increasing to 200hours after 7 days of aging, for a 20 g/sqm of coating deposited on thetest panel before more than 5% of the surface of the test panel wascovered by red rust. Aging of the formulation did not affect theperformance of the coating.

This example shows that an Epoxy silane Oligomer, in accordance with thepresent invention, combined with a vinyl ethoxy silane used at thedispersion stage of zinc and aluminium provides very good stability andcorrosion protection. The system is a real one-pack system withexcellent durability. In addition, this system outperforms the coatingsdescribed above in Examples 4 and 5.

EXAMPLE 10 Using EXO Example 5 Combined with a Cycloaliphatic EpoxySilane Triethoxy and the Procedures Described in FIG. 3

In this example, the ESO Example 5 was pre-solubilized in water usingthe formulation described with respect to Table 4 and combined with acycloaliphatic epoxy triethoxy silane (Coatosil® 1770 available from GESilicones) during the dispersion stage.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added in the beaker: 18.96 weight %of demineralized water, 0.59 weight % of boric acid, 3.3 weight % ofDowanol® DPM and 4.15 weight % of ESO Example 5 described above herein.The solution was mixed for 18 hours until a clear solution was obtained.

Then, the following ingredients were added while stirring: 33.8 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5 weight% of APEO surfactant (HLB 9—Berol® 26), and additional 2.9 weight % ofcycloaliphatic epoxy triethoxy silane (Coatosil® 1770 available from GESilicones).

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % of aluminium powder Chromal VII.Finally, 0.4 weight % of Aerosol OT 75 was added to the finaldispersion. The final product was then stored for 2 days and 7 daysbefore application and testing. Application and testing conditions werethe same as those described above in Example 4. Results for example 10are described below.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 10 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 10.3 hours/g HSS Red Rust 5%  3.5 hours/g

Example 10 On a CRS Test Panel After 7 Days of Aging

Adhesion 1 - little loss of adhesion Powdering resistance Excellent NSSRed rust 5% 9.8 hours/g HSS Red Rust 5% 2.5 hours/g

Corrosion resistance achieved by the combination of ESO Example 5described herein with addition of a cycloaliphatic tri-ethoxy silane(e.g., Coatosil® 1770 available from GE Silicones) at the dispersionstage provided about 200 hours of protection on a CRS test panel after 2or 7 days of aging for a 20 g/sqm of coating deposited on the test panelbefore more than 5% of the surface of the test panel was covered by redrust. Aging of the formulation did not affect the performance of thecoating.

This example shows that an Epoxy silane Oligomer, in accordance with thepresent invention, combined with a cycloaliphatic triethoxy silane(Coatosil® 1770 available from GE Silicones) used at the dispersionstage of zinc and aluminium provides very good stability and corrosionprotection. The system in this case is a real one-pack system withexcellent durability. In addition, this system outperforms the coatingsdescribed in Examples 4 and 5 above.

EXAMPLE 11 Using ESO Example 5 Described Herein Above Combined with aPropyl Triethoxy Silane and the Procedure Described in FIG. 3

In this example, the ESO Example 5 was pre-solubilized in water usingformulation described above with respect to Table 4 and combined with anon-organo reactive triethoxy silane (e.g., Silquest® A-138 availablefrom GE Silicones) during the dispersion stage.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added in the beaker: 18.96 weight %of demineralized water, 0.59 weight % of boric acid, 3.3 weight % ofDowanol® DPM and 4.15 weight % of ESO Example 5. The solution was thenfor 18 hours until a clear solution was obtained.

Then, the following ingredients were added while stirring: 34.7 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5 weight% of APEO surfactant (HLB 9—Berol® 26), and an additional 2.0 weight %of propyl triethoxy silane (e.g., Silquest® A-138 available from GESilicones).

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % of aluminium powder Chromal VII.Finally, 0.4 weight % of Aerosol® OT 75 was added to the finaldispersion. The final product was then stored for 2 days and 7 daysbefore application and testing. Application and testing conditions werethe same as those described above in Example 4. Results for Example 11are discussed below.

The Product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 11 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 7.6 hours/g HSS Red Rust 5% 2.2 hours/g

Example 11 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 6.3 hours/g HSS Red Rust 5% 2.4 hours/g

Corrosion resistance achieved by a combination of ESO Example 5 withcombined addition of propyl triethoxy silane (e.g., Silquest® A-138available from GE Silicones) at the dispersion stage provided about 120hours of protection on a CRS test panel after 2 or 7 days of aging for20 g/sqm of coating deposited on the surface of the test panel beforemore than 5% of the surface of the test panel was covered by red rust.Even though the performances are slightly lower compared to Example 7,it is interesting to note that a non-reactive silane can be used at thedispersion stage together with an ESO, in accordance with the presentinvention, to provide a stable waterborne zinc rich composition havingimproved corrosion resistance.

EXAMPLE 12 Using ESO Example 3 and the Procedure Described in FIG. 4

In this example, the ESO example 3 was pre-solubilized in water with theformulation described above with respect to Table 4 in using acombination of boric acid, Dowanol® DPM and surfactant. Thepre-solubilized ESO was then used alone in a dispersion includingmetallic powders. This example represents a more simple process ofmanufacturing, as no further addition is needed at the dispersion stage.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added in the beaker: 33.62 weight %of demineralized water, 0.58 weight % of boric acid, 4.8 weight % ofDowanol® DPM, 1.5 weight % of APEO HLB 13 surfactant (Berol® 09) and 6.6weight % of ESO Example 3. The solution was mixed for 18 hours or untila clear solution was obtained.

Then following ingredients were then added while stirring: 19.6 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), and 1.5 weight % of APEO surfactant (HLB 9—Berol® 26).

The components were mixed together for ten minutes. Next, the followingmetallic fillers were added under agitation: 28.0 weight % of Zinc flakeGTT followed by 3.0 weight % of aluminium powder Chromal VII. Finally,0.4 weight % of Aerosol OT 75 was added to the final dispersion. Duringintroduction of the components, the speed of the agitator wasprogressively increased in order to maintain appropriate dispersiontorque. Dispersion was maintained for 4 hours. The final product wasthen stored for 2 days, 7 days and three months before application andtesting. The application and testing conditions were the same as thosedescribed in Example 4. Results for Example 12 are discussed below.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 12 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Medium NSS Redrust 5% 11.5 hours/g HSS Red Rust 5%  2.4 hours/g

Example 12 On a CRS After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Medium NSS Redrust 5% 15.4 hours/g HSS Red Rust 5%  4.5 hours/g

Corrosion resistance achieved by the use of ESO Example 3 as solecomponent in a one step process provided about 230 hours of protectionon a CRS test panel after 2 days of aging and increasing to over 300hours after 7 days of aging for 20 g/sqm of coating deposited on thetest panel before more than 5% of the surface of the test panel wascovered by red rust.

The performances achieved with this specific ESO significantlyoutperformed a conventional system based on pure monomeric silanes suchas Examples 4 and 5. This system is a real one-pack system withexcellent durability. The process of manufacturing is simpler thanExample 4 and would thus impact manufacturing cost for water borneprotective coatings.

EXAMPLE 13 Using ESO Example 2 and the Procedure Described in FIG. 4

In this example, ESO Example 2 was pre-solubilized in water usingformulation described above with respect to Table 4 in a combination ofboric acid, Dowanol® DPM and a surfactant. This ESO solubilized fasterand was used alone in a dispersion of metallic powders. This examplerepresents a more simple and shorter process of manufacturing, as nofurther addition at the dispersion stage was required.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added in the beaker: 33.62 weight %of demineralized water, 0.58 weight % of boric acid, 4.8 weight % ofDowanol® DPM, 1.5 weight % of APEO HLB 13 surfactant (Berol® 09) and 6.6weight % of ESO Example 2. The solution was mixed for 2 hours or until aclear solution was obtained.

Then, the following ingredients were added while stirring: 19.6 weight %of demineralized water, 0.4 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), and 1.5 weight % of APEO surfactant (HLB 9—Berol® 26).

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % of Aluminum powder Chromal VII.Finally, 0.4 weight % of Aerosol® OT 75 was added to the finaldispersion. During introduction, the speed of the agitator wasprogressively increased in order to maintain appropriate dispersiontorque. Dispersion was maintained for 4 hours. The final product wasthen stored for 2 or 7 days and three months before application andtesting. Application and testing conditions are the same as thosedescribed above for Example 4. Results for Example 13 are discussedbelow.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 13 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 12.0 hours/g HSS Red Rust 5%  3.1 hours/g

Example 13 On a CRS Test Panel After 7 Days Aging

Adhesion 0 - No loss of adhesion Powdering resistance Poor NSS Red rust5% 9.6 hours/g HSS Red Rust 5% 2.5 hours/g

Corrosion resistance achieved by ESO Example 2, as a sole component in aone step process, was about 240 hours of protection on a CRS test panelafter 2 days of aging and over 190 hours after 7 days of aging for 20grams/m² of coating deposited on the test panel before more than 5% ofthe surface of the test panel was covered by red rust. The process ofmanufacturing is simpler than Example 4 and would thus impactmanufacturing cost for water borne protective coatings.

EXAMPLE 14 Using ESO Example 6 Combined with a Monomeric Epoxy Silaneand the Procedure Described in FIG. 4

In this example, ESO Example 6 was pre-solubilized in water inconjunction with a glycidoxy triethoxy silane (Silquest® A-1871) usingthe formulation described above with respect to Table 4 and in acombination of boric acid and Dowanol® DPM. The ESO solubilized togetherwith the monomeric silane was used directly for the dispersion of themetallic powders. This example represents a more simple process ofmanufacturing because no further addition at the dispersion stage wasrequired.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added in the beaker: 22.68 weight %of demineralized water, 0.77 weight % of boric acid, 3.85 weight % ofDowanol® DPM, 4.8 weight % of ESO Example 6 and 2.9 weight % ofglycidoxy tri ethoxy silane (Silquest® A-1871). The solution was mixed 4hours until a clear solution was obtained.

Then, the following ingredients were added while stirring: 30.4 weight %of demineralized water, 0.2 weight % of Hydroxyethylcellulose (Natrosol®HHR 250), 1.5 weight % of APEO surfactant (HLB 13—Berol® 09) and 1.5weight % of APEO surfactant (HLB 9—Berol® 26).

The components were mixed together during ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % Aluminum powder Chromal VII.Finally, 0.4 weight % of Aerosol OT 75 was added to the finaldispersion. During introduction, the speed of the agitator wasprogressively increased in order to maintain appropriate dispersiontorque. Dispersion was maintained for 1 hour. The final product was thenstored for 2 or 7 days and three months before application and testing.

Application and testing conditions were the same as those describedabove for Example 4. Results for Example 14 are discussed below.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 14 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 9.6 hours/g HSS Red Rust 5% 3.0 hours/g

Example 14 On CRS After 7 Days Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 9.4 hours/g HSS Red Rust 5% 3.1 hours/g

Corrosion resistance achieved by a combination of ESO Example 6 withglycidoxy tri ethoxy silane (e.g., Silquest® A-1871) used in a one stepprocess was about 190 hours of protection on a CRS test panel after 2 or7 days of aging for 20 grams/sqm of coating deposited on the test panelbefore more than 5% of the surface was covered by red rust.

The performances achieved with this specific ESO and epoxy silanemonomer combination was with respect to total processing time, which wasonly 5 hours in total.

Product was a one-pack system with good performance.

EXAMPLE 15 Using ESO Example 6 Alone and Directly Solubilized andDispersed in Water and Metallic Powders and the Procedure Described inFIG. 5

In this example, ESO Example 6 was not pre-solubilized in water prior tothe dispersion of pigments. Instead, the ESO was directly added in theformulation using all components and mixed to obtain a homogeneousmixture. The homogeneous mixture was not in a soluble phase until all ofthe metallic powders were added and dispersed for about 6 hours. Thisprocedure, as described FIG. 5, is a one step process.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added in the beaker: 52.49 weight %of demineralized water, 0.51 weight % of boric acid, 5.4 weight % ofDowanol® DPM, 7.7 weight % of ESO Example 6, 0.2 weight % ofHydroxyethylcellulose (Natrosol® HHR 250), 1.5 weight % of APEOsurfactant (HLB 13—Berol® 09) and 1.5 weight % of APEO surfactant (HLB9—Berol® 26).

The components were mixed together for ten minutes. Next, the followingmetallic fillers were added under agitation: 28.0 weight % of Zinc flakeGTT followed by 3.0 weight % of Aluminum powder Chromal VII. Finally,0.4 weight % of Aerosol OT 75 was added to the final dispersion. Duringintroduction of the components and ingredients, the speed of theagitator was progressively increased in order to maintain appropriatedispersion torque. Dispersion was maintained for 6 hours.

The final product was then stored for 2 or 7 days and three monthsbefore application and testing. Application and testing conditionsapplied in this example were the same as those described above inExample 4. Results for Example 15 are discussed below.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 15 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 9.4 hours/g HSS Red Rust 5% 2.9 hours/g

Example 15 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 8.3 hours/g HSS Red Rust 5% 3.8 hours/g

Corrosion resistance achieved by ESO Example 6 used in a directdispersion process provided about 180 hours of protection on a CRS testpanel after 2 or 7 days of aging for 20 grams/sqm of coating depositedon the test panel before more than 5% of the surface of the test panelwas covered by red rust.

The performance achieved with this specific ESO was the total processingtime was only 6 hours. This product is a one-pack system with goodperformance.

EXAMPLE 16 Using ESO Example 6 Alone which was Directly Solubilized andDispersed in Water and Metallic Powders and Using the ProcedureDescribed in FIG. 5

In a metallic beaker equipped with mechanical agitation and Cowlesblade, the following components were placed in the beaker: 52.49 weight% of demineralized water, 0.51 weight % of boric acid, 5.4 weight % ofDowanol® DPM, 0.2 weight % of Hydroxyethylcellulose (Natrosol® HHR 250),1.5 weight % of APEO surfactant (HLB 13—Berol® 09), 1.5 weight % of APEOsurfactant (HLB 9—Berol® 26) and 7.9 weight % of Silquest® A-187.

The components were mixed together for ten minutes. Next, the followingmetallic fillers were added under agitation: 28.0 weight % of Zinc flakeGTT followed by 3.0 weight % of Aluminum powder Chromal VII. Finally,0.4 weight % of Aerosol OT 75 was added to the final dispersion. Duringintroduction of the ingredients, the speed of the agitator wasprogressively increased in order to maintain appropriate dispersiontorque. Dispersion was maintained for 6 hours. The product was storedfor stability examination and showed a strong hydrogen evolution afterless than one hour.

Monomeric silane (e.g., Silquest® A-187) cannot be used in a directdispersion process with metallic powders as the ESOs in accordance withthe present invention, e.g., ESO Example 6.

This example illustrates a major difference between a regular monomericsilane and inventive Epoxy Silane Oligomers of current inventiondisclosure.

EXAMPLE 17 Using EXO Example 9 and the Procedure Described in FIG. 4

In this example, the ESO example 9 was pre-solubilized in water with theformulation described below in using a combination of boric acid,Dowanol® DPM and surfactant. The pre-solubilized ESO was then used alonein a dispersion including metallic powders. This example represents amore simple process of manufacturing, as no further addition is neededat the dispersion stage. This example illustrates the application of anepoxy alkylene oxide silane co-oligomers, in accordance with anembodiment of the present invention, in zinc rich water borne protectivecoatings.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following components were added in the beaker: 32.00 weight %of demineralized water, 0.77 weight % of boric acid, 5.25 weight % ofDowanol® DPM, and 7.0 weight % of ESO Example 9. The solution was mixedfor 18 hours or until a clear solution was obtained.

Then, the following ingredients were added while stirring: 23.7 weight %of demineralized water, 1.5 weight % of APEO HLB 13 surfactant (Berol®09), 0.4 weight % of Hydroxyethylcellulose (Natrosol® HHR 250), and 1.5weight % of APEO surfactant (HLB 9—Berol® 26).

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % of aluminium powder Chromal VII.Finally, 0.4 weight % of Aerosol® OT 75 available from Cytec Industries,Inc. was added to the final dispersion. During introduction of thecomponents, the speed of the agitator was progressively increased inorder to maintain appropriate dispersion torque. Dispersion wasmaintained for 4 hours. The final product was then stored for 7 daysbefore application and testing. The final pH of the formulation wasstabilized at 6.9 and the viscosity was at 35 seconds with DIN cupnumber 4.

The application and testing conditions were the same as those describedin Example 4. Results for Example 17 are discussed below.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 17 On a CRS After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 13.4 hours/g HSS Red Rust 5%  4.0 hours/g

Corrosion resistance achieved by the use of ESO Example 9 as solecomponent in a one step process provided about 270 hours of protectionon a CRS test panel after 7 days of aging for 20 g/sqm of coatingdeposited on the test panel before more than 5% of the surface of thetest panel was covered by red rust.

The performance achieved with this specific ESO significantlyoutperformed a conventional system based on pure monomeric silanes suchas Examples 4 and 5. This system is a real one-pack system withexcellent durability. The process of manufacturing is simpler thanExample 4 and would thus significantly reduce the cost associated withmanufacturing a waterborne protective coating.

It is also observed that it has been possible to increase to theconcentration of ESO in the hydrolysis phase of the process. Thecosolvent content in Dowanol® DPM was also lower compare to otherexamples, e.g. Examples 2 to 12.

This indicates that the co-oligomer of an epoxy silane and an alkyleneoxide can increase the solubilization rate as well as reduce the amountof coalescent needed to make the ESO water-soluble. Corrosionperformances are not affected by the contribution of alkylene oxide intothe ESO as prepared in Example 9.

EXAMPLE 18 Using an Epoxy Silane Oligomer Solution of Dynasilan® HS 2926and the Procedure Described in FIG. 4

A pre-solubilized Epoxy Silane Oligomer according to present inventiondisclosure does not perform similarly to Epoxy Silane Oligomer made inwater as currently exists commercially with a product called Dynasilan®HS 2926 (Available from Degussa Huls).

In this example, a comparison was made between the material Dynasilan®HS 2926 in the same formulation as described above in Examples 12 and13.

The product was used at equal loading of siloxane assuming that the drycontent given for the product was 40% of non volatile as indicated. Inthis case, the HS 2926 was already solubilized in water and was directlyused for the dispersion of the metallic powders.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following ingredients were added while stirring: 16.6 weight% of Dynasilan® HS 2926, 43.62 weight % of demineralized water, 0.58weight % of boric acid, 1.5 weight % of APEO surfactant (HLB 13—Berol®09), 1.5 weight % of APEO surfactant (HLB 9—Berol® 26), and 4.8 weight %of Dowanol DPM.

The components were then mixed together for ten minutes. Next, thefollowing metallic fillers were added under agitation: 28.0 weight % ofZinc flake GTT followed by 3.0 weight % of Aluminum powder Chromal VII.Finally, 0.4 weight % of Aerosol OT 75 was added to the finaldispersion. During introduction of the components, the speed of theagitator was progressively increased in order to maintain appropriatedispersion torque. Dispersion was maintained for 4 hours.

The product was stored and followed with respect to stability. After acouple of hours, strong hydrogen evolution occurred, and the productgenerated a significant quantity of foam. Thus, indicating that poorstability of the product as compared to formulations in Examples 12 and13.

This example illustrates that the structure of the ESOs in accordancewith the present invention provided stable products with varying watersolutions as compared to an already hydrolyzed epoxy silane oligomer(e.g., Dynasilan® HS 2926).

Water Borne Pigment Dispersions and Their Uses EXAMPLE 19 Aluminum PasteDispersion Prepared Using the Procedure Described in FIG. 6

The process used in this example was similar to the process used inExample 12 described above except that the aluminum powder was usedalone at a higher concentration (36.1% instead of 28% of Zinc togetherwith 3% of Aluminum).

The ratio of silane to the pigment was adjusted to 1 of the ESO to 9 ofthe aluminum. The purpose here is to prepare aluminum concentrates thancan be further extended with additional binders to formulate aluminumcontaining coatings.

In a metallic beaker equipped with mechanical agitation and Cowlesblade, the following ingredients were added while stirring: 56.23 weight% of demineralized water, 0.47 weight % of boric acid, 0.94 weight % ofAPEO surfactant (HLB 13—Berol® 09), 0.94 weight % of APEO surfactant(HLB 9—Berol® 26), 2.7 weight % of Dowanol® DPM and 3.41 weight % of ESOExample 6. The components were dispersed for 18 hours until clearsolution was obtained. Next, 35.3 weight % Aluminum powder Chromal VIIwas added. During introduction of the ingredients, the speed of theagitator was progressively increased in order to maintain appropriatedispersion torque. Dispersion was maintained for 4 hour.

The obtained product was stored for 2 months and followed with respectto stability. During this period of aging no hydrogen evolution wasobserved. A settlement was observed but was easily re-suspended withgentle stirring.

EXAMPLE 20 Zinc Powder Pigment Paste

The same procedure, see FIG. 6, was applied in this example as inExample 18 for aluminium except in this example Zinc powder was used inlieu of Aluminum powder. Due to the higher density of the zinc powder,the Zinc content was increased up to 56 weight %. The purpose here is toprepare zinc concentrates than can be further extended with additionalbinders to formulate aluminum containing coatings.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following ingredients were added while stirring: 33.1 weight% of demineralized water, 0.60 weight % of boric acid, 1.3 weight % ofAPEO surfactant (HLB 13—Berol® 09), 1.3 weight % of APEO surfactant (HLB9—Berol® 26), 3.4 weight % of Dowanol® DPM and 4.30 weight % of ESOExample 6.

The components were dispersed for 18 hours until clear solution wasobtained. Next, 56 weight % of Zinc flake GTT was added while stirringand dispersed. During introduction of the components, the speed of theagitator was progressively increased in order to maintain appropriatedispersion torque. Dispersion was maintained for 4 hours.

The obtained product was stored for 2 months and followed with respectto stability. During this period of aging no hydrogen evolution wasobserved. A settlement was observed but was easily re-suspended withgentle stirring.

EXAMPLE 21 Protective Coating by Pigment Paste Mixing Using theProcedure Described in FIG. 7

In this example the zinc and aluminum content used in the previousExample 5 and following were introduced using the aluminum and zincpastes prepared respectively according to Examples 19 and 20. The twopastes are simply mixed with ESO solution as described in previousexamples.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following ingredients were added while stirring: 23.87 weight% of demineralized water, 0.74 weight % of boric acid, 4.1 weight % ofDowanol® DPM and 5.29 weight % of ESO Example 6. The components weremixed for 18 hours until a clear solution was obtained.

Next, 50 weight % of Zinc paste (Example 20) and 8.5 weight % ofaluminium paste (Example 19) followed by 0.4 weight % of Aerosol OT 75,0.15 weight % of Natrosol® 250 HRR in 6.95 weight % of demineralizedwater were added while stirring and mixed for 30 minutes.

Application and testing conditions were the same as those discussedabove in Example 4. Results for Example 21 are discussed below.

The product was stable upon storage and no hydrogen evolution wasobserved indicating a good protection of metallic particles by silanecoupling.

Example 21 On a CRS Test Panel After 2 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 8.5 hours/g HSS Red Rust 5% 3.1 hours/g

Example 21 On a CRS Test Panel After 7 Days of Aging

Adhesion 0 - No loss of adhesion Powdering resistance Excellent NSS Redrust 5% 8.4 hours/g HSS Red Rust 5% 3.3 hours/g

Corrosion resistance achieved by the formulation of this exampleprovided about 170 hours of protection on a CRS test panel after 2 or 7days of aging for 20 grams/sqm of coating deposited on the test panelbefore more than 5% of the surface of the test panel was covered by redrust. Product is still a one-pack system with good performance.

It was observed according to Examples 19 and 20 can be used as a simpleblend or mixed with additional binder systems based on ESO prepared inaccordance with the present invention. It was also observed that thezinc and aluminium pastes prepared in Examples 19 and 20, in accordancewith exemplary embodiments of the present invention, can be combinedwith a monomeric silane or other epoxy silane oligomer solutions astested in Example 18.

EXAMPLE 22 Metallic Inks or Coating by Pigment Paste Mixing

In Examples 19 and 20, it was demonstrated that the pigment pastesdisclosed therein could be used in a simple blend with a conventionalstyrene acrylic resin as typically employed in the printing ink andcoating industry. In the present example, a styrene acrylic latex wasselected and simply mixed with an aluminium paste according to followingprocedure.

In a metallic beaker equipped with mechanical agitation and a Cowlesblade, the following ingredients were added while stirring: 60 weight %of a styrene acrylic latex (e.g., Worleecryl® 8410 available from WorleeGmbh) and 60 weight % of aluminum paste produced according to Example 19discussed above. The components were mixed for 10 minutes.

This example (referring to “ESO based Al” in following Table 8 below)illustrates that it is possible to prepare aluminium-based coatings orinks by simply mixing a pre-dispersed aluminium with a solubilized ESO,in accordance with the present invention.

In order to compare the performance and stability of such a preparation,a dispersion of the same aluminum powder was made directly into astyrene-acrylic latex selected according to following procedure:

In a metallic beaker equipped with mechanical agitation and Cowlesblade, the following ingredients were added while stirring: 84.0 weight% of Worleecryl® 8410 (styrene acrylic resin available form WorleeGmbh), 1.0 weight % of APEO surfactant (HLB 13—Berol® 09), 1.0 weight %of APEO surfactant (HLB 9—Berol® 26). The components were mixed for 10minutes. Next, 14.0 weight % of aluminium powder Chromal VII was added.During introduction of the aluminium, the speed of the agitator wasprogressively increased in order to maintain appropriate dispersiontorque. Dispersion was maintained for 30 minutes.

This example (referring to “Direct dispersion process” in Table 8 below)illustrates the typical preparation used to make an aluminium-basedcoating or ink in styrene acrylic latexes.

TABLE 8 Direct Paste dispersion process ESO based Al Worleecryl ® 841084 parts 60 parts (available from Worlee Gmbh) Berol ® 09  1 part /Berol ® 26  1 part / Aluminum powder Chromal VIII 14 parts / Aluminumpaste / 40 parts (ESO Example 19) Operation Disperse 30 minutes Mix 10minutes

The formulation prepared according to the direct dispersion mode was notstable at all. The direct dispersion product experienced strong degazingand foaming during first hours of storage. Whereas, the product based onESO dispersed paste was very stable for more than 2 months.

The simple blend of the ESO aluminum paste, in accordance with thepresent invention, was stable and could be applied using standard handdrawer on paper.

The coating realized has very good printing quality as well as gloss.Similar behaviour was achieved by the use of the Zinc paste dispersed inESO. Such combination of Zinc paste with anionic resins could give thepossibility to prepare zinc rich coatings based on latexes ordispersions or shop primers.

EXAMPLE 23

In another aspect of the use of current ESOs, it was demonstrated infollowing example that it is possible to use an ESO as externalcrosslinker for waterborne latexes. It is known in prior art that Epoxysilane monomers can be used as crosslinkers in anionic or cationic-basedlatexes and water dispersions. In following examples, a typical woodcoating formulation was used as model system to show what the influencethe current ESOs have on such formulations as well as to compare the useof the current ESOs to conventional epoxy silane monomers. Formulationwas prepared according to Table 9 below using the following procedure.

In a metallic beaker equipped with mechanical agitation and Cowlesblade, the following ingredients were added while stirring: 69.52 weight% of Acrylic latex SCX® 8225 (Available from SC Johnson Polymer), 1.185weight % of Wetlink 78 (formulation 2 in Table 9) or 1.185 weight %Epoxy Silane Oligomer ESO Example 5 (formulation 3 in Table 9). Theformulation was stirred for 30 minutes. Next, added to the formulationwas 0.2 weight % of a wetting agent (e.g., Coatosil® 1211 available fromGE Silicones), 9.0 weight % of Coalescent (e.g., Proglyde® DPnBavailable from Dow Chemical), 4.3 weight % of matting wax (e.g.,Aquamat® 128 available from Byk Cera), 2.5 weight % of PE wax (Ultralub®D819 available from Keim-Additec Surface) and a necessary amount ofwater to make 100 weight %. The components were then mixed for 30minutes. As a non-modified standard, the same formulation was appliedwithout any silane (formulation 1 is listed in Table 9).

Typical epoxy silanes used as an external crosslinker for anioniclatexes was used for comparison to gamma-glycidoxypropylmethyldiethoxysilane (Wetlink® 78 available from GE Silicones).

TABLE 9 Formulation Formulation Formulation 1 Formulation 2 3 Acryliclatex SCX ® 69.52 69.52 69.52 8225 (Available from SC Johnson Polymer),weight percent Water, weight percent 9.48 8.295 8.295 Epoxy silane(e.g., 1.185 Wetlink ® available from GE Silicones), weight percentEpoxy Silane Oligomer 1.185 (ESO Example 5), weight percent WettingAgent (e.g., 0.2 0.2 0.2 Coatosil ® 1211 available from GE Silicones),weight percent Coalescent (e.g., 9 9 9 Proglyde ® DPnB available fromDow Chemical), weight percent Matting Wax (e.g., 4.3 4.3 4.3 Aquamat ®128 available from Byk Cera), weight percent PE wax (Ultralub ® 2.5 2.52.5 D819 available from Keim-Additec Surface), weight percent Water,weight percent 5 5 5

In a first set of tests applied on the modified polymers, the mixturesof acrylic latex with water and corresponding epoxy silane monomer oroligomer were applied in Teflon cells after appropriate curing at roomtemperature for 15 days. Films so formed were then peeled out of theTeflon cells and accurately weighed before immersion in water. Waterabsorption and polymer remaining after further drying was measured. Gelcontent was also measured on the same samples.

Results are given in Table 10 below.

TABLE 10 Formulation Formulation Formulation Formulation 1 2 3 Waterabsorption (percent Dissolved 25% 22% of water absorbed) Waterresistance (percent 77% 98% 98% of polymer remaining after drying at RT)Gel content (percent of  0% 94% 95% polymer left after 8 hours ofextraction in MEK)

The results show that an ESO, in accordance with the present invention,significantly enhances the water resistance of anionic latexes to alevel at least comparable to Epoxysilane monomers.

In a second set of tests, full coatings of Formulations 1-3 were appliedon glass substrates in order to allow measurement of hardness. 200microns of the coatings were applied on the glass substrates and driedfor increasing period of time during which Koenig Hardness was followed.Table 11 below shows the hardness evolution of the films.

TABLE 11 Koenig Hardness (Seconds) Time of drying FormulationFormulation (days @ 23° C.-50% HR) Formulation 1 2 3 1 29.8 36.4 36.8 482.6 84.0 85.8 7 84.0 86.8 89.6 11 88.7 91.0 90.0 16 93.3 93.8 97.0 2291.4 93.8 97.1

The results show that an ESO, e.g., ESO Example 5 significantly enhancesthe hardness of the wood coating. In fact, the results were even betterthan the use of a conventional epoxy silane monomer.

Finally, the full Formulations 1-3 were applied on wood panels (oakplywood) using a spray gun. A deposit of 150 g/sqm was applied andfurther dried for 15 days at room temperature.

Staining resistance was then tested according to the conditions listedin Table 12 below. Results are illustrated in Table 13 below.

TABLE 12 Spot test according to the test method DIN 68861 - 1B Coatingsare cured 15 days at room temperature Liquid test: Acetone 10 secondsAmmonia 10%  2 minutes Ethanol 48% 60 minutes Isopropanol 50% 60 minutesAcetic acid 60 minutes Ethyl-butyl acetate 10 seconds Deposit: 30 μlcovered with glass cup Rating: (0): no change (1): minor changes ingloss or color (2): changes in gloss or color but no surface damage (3):major changes visible but no real damage of the surface (4): majorchanges visible and surface damage (5): most of the exposed surfacedamaged

TABLE 13 Chemical resistance (DIN68861-1B) Staining agent- contactFormulation Formulation time Formulation 1 2 3 Acetic acid- 60 minutes 50 1 Ammonia (10%)- 2  5**  5* 2 minutes Ethylalcohol(48%)- 60 0 0 0minutes Isopropanol(50%)- 60 0 0 0 minutes Acetone- 10 seconds 3 1 1Ethyl-Butyl acetate- 10 3 1 0 seconds *= surface of coating is notphysically damaged but staining of wood is visible **= surface ofcoating is physically damaged and strong staining is visible.

Here again, the results show that ESO Example 5 significantly enhancesthe chemical resistance and staining resistance of a wood coating. Theeffect is most particularly quite obvious in staining resistance againstammonia solution for which the wood staining is significantly reduced.

This example test exhibits the possibility to use ESO as externalcrosslinkers into acrylic latexes or also as anti stain agent for woodcoatings.

While exemplary embodiments have been shown and described, it will beunderstood by those skilled in the art that various modifications andsubstitutions may be made thereto without departing from the spirit andscope of the invention. Accordingly, it is to be understood that thepresent invention has been described by way of illustrations and notlimitation.

1. A process for producing a waterborne coating composition comprisingan epoxysilane oligomer, a particulate metal, a surfactant and water,said method comprising: reacting glycidoxy silane having 2 alkoxy groupswith water in the presence of a catalyst selected from the groupconsisting of an ion exchange resin, an alkylammonium salt, and areaction product of a quaternary ammonium organofunctional silane and aceramic, silica gel, precipitated silica, alumina or aluminosilicatesupport, wherein said water is continuously fed during the reaction andthe molar ratio of water to silane monomer is from 0.1 to 1.5.
 2. Theprocess of claim 1, wherein the molar ratio of water to silane monomeris from 0.4 to 1.0.
 3. The process of claim 1, wherein the molar ratioof water to silane monomer is from 0.1 to 0.5.
 4. The process of claim 1wherein the catalyst is at least one member selected from the groupconsisting of, hexadecyltrimethylammonium chloride,tetra-n-butylammonium chloride, benzyl trimethylammonium chloride,hexadecyltrimethylammonium bromide, tetra-n-butylammonium bromide,benzyl trimethylammonium bromide, hexadecyltrimethylammonium hydroxide,tetra-n-butylammonium hydroxide and benzyl trimethylammonium hydroxide.5. The process of claim 1 wherein the glycidoxy silane is selected fromthe group consisting of gamma-glycidoxypropyl methyldimethoxysilane andgamma-glycidoxypropyl methyldiethoxysilane.
 6. The process of claim 1which further comprises continuously removing by-product alcoholproduced during the reaction.
 7. A waterborne coating composition,comprising: a particulate metal; a surfactant; epoxy silane oligomermade by the process of reacting glycidoxy silane having 2 alkoxy groupwith water in the presence of a catalyst selected from the groupconsisting of an ion exchange resin, an alkylammonium salt, and areaction product of a quaternary ammonium organofunctional silane and aceramic, silica gel, precipitated silica, alumina or aluminosilicatesupport, wherein said water is continuously fed during the reaction andthe molar ratio of water to silane monomer is from 0.1 to 1.5; water;and, one or more optional ingredients selected from the group consistingof pH adjusting agent, cosolvent, epoxy silane monomer, surfactant,binder, and pigment paste dispersion.
 8. The waterborne coatingcomposition of claim 7 wherein the particulate metal is present in anamount of from 0.1 to 80 weight percent, the surfactant is present in anamount of from 0.05 to 10 weight percent, the epoxy silane oligomer ispresent in an amount of from 0.1 to 30 weight percent, and water ispresent in an amount of from 5 to 99 weight percent.
 9. The waterbornecoating composition of claim 7 wherein the particulate metal is selectedfrom the group consisting of finely divided aluminum, manganese,cadmium, nickel, stainless steel, tin, ferroalloys, magnesium and zinc.10. The waterborne composition of claim 7 including a pH adjusting agentcomprising at least one member selected from the group consisting ofboric acid, orthophosphoric acid, acetic acid, and citric acid in anamount sufficient to provide a pH of from 4 to
 6. 11. The waterbornecomposition of claim 7 including a co-solvent present in an amount offrom 0.1 to about 60 weight percent based upon the total weight of thecomposition, wherein said co-solvent is at least one member of the groupconsisting of dipropylene glycol methyl ether, ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonopropyl ether, ethylene glycol monobutyl ether, ethylene glycolmonomethyl ether acetate, ethylene glycol monohexyl ether, ethyleneglycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether,diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,diethylene glycol monopropyl ether, diethylene glycol monobutyl ether,butyl carbitol, dipropylene glycol dimethyl ether, butyl glycol,butyldiglycol, ethylene glycol monobutyl ether acetate, diethyleneglycol monoethyl ether acetate, diethylene glycol monobutyl etheracetate, n-propyl acetate, n-butyl acetate, isobutyl acetate,methoxypropylacetate, butyl cellosolve actetate, butylcarbitol acetate,propylene glycol n-butyl ether acetate, t-butyl acetate, n-butanol,n-propanol, isopropanol and ethanol.
 12. The waterborne composition ofclaim 7 including an epoxy silane monomer present in an amount of up to10 weight percent based on the total weight of the composition, whereinsaid epoxy silane monomer is selected from the group consisting ofgamma-glycidoxypropyl trimethoxy silane, gamma-glycidoxypropyl triethoxysilane, gamma-glycidoxypropyl methyldimethoxy silane andgamma-glycidoxypropyl methyldiethoxy silane.
 13. An adhesive, sealant orcoating composition which comprises the waterborne composition of claim7.